14th International Ceramics Congress
Poster Presentations

CA:P02  Synthesis of α-cordierite Powder from Preheated Kaolinite, Talc and Alumina
HSIN-WEN FAN, FU SU YEN, National Cheng Kung University, Tainan, Taiwan

Synthesis of cordierite (2MgO∙2Al2O3∙5SiO2) composites is normally fabricated by high temperature treatments using mineral powders of kaolinite, talc and synthetic alumina . As the former two are phyllosilicates that containing Mg(OH)2 and Al(OH)3 layers in the structures, or simply minerals with crystalline water. Heat treatments to remove the crystalline water were performed firstly. The minerals were transformed into mullite and enstatite accompanied with releasing amorphous silica. The two transition phases then react with alumina to form cordierite. In this study, preheat treatments at 700℃ and 900℃ for 30 minutes were selected. Studies were concentrated on which temperature will be appropriate for the preheat treatment that will lead to the easy formation of α-cordierite. The preheated kaolinite and talc were mixed with alumina. The mixtures were compacted to pellets and then were heated at several specific temperatures. It is found that the kaolinite preheated at 700℃ is better for the fabrication of α-cordierite, because it provides a higher active state of silica. The silica is easier to react with alumina to form mullite and the subsequence of spinel. As a result, a relative large amount of spinel is formed that leading to the formation of α-cordierite.


CA:P03  Synthesis of NIR-reflective CoFe2O4 Black Pigment Doped with CaO and Al2O3 Derived from Minerals
N. SANGWONG, M. SUWAN, S. SUPOTHINA, National Metal and Materials Technology Center, National Science and Technology Development Agency (NSTDA), Klong Luang, Pathum Thani, Thailand

An increasing demand for energy consumption of air-conditioning system has driven research in the field of energy-efficient roofs. A solar-reflective coating has been employed to reflect solar radiation, particularly in the near-infrared (NIR) region. Despite of their low NIR reflectance, dark-shaded roofs are preferred due to their aesthetic appearance. Thus, it becomes important to develop dark pigment with high NIR reflectance. In this work, CoFe2O4 black pigment has been synthesized by solid-state reaction of Co3O4 and Fe2O3 at 1100-1200oC for 3 h. Its lightness value (L*) was 19.59, and the NIR reflectance (R) was 17.5%. Various amounts of calcite or gypsum and bauxite were added into raw materials as a source of CaO and Al2O3 dopants, respectively, to form CaO- and Al2O3-doped CoFe2O4 to manipulate its color hue and NIR reflectance. The incorporation of dopants resulted in a slight decrease of blackness (increase of L*) and an increase of NIR reflectance. A series of black pigments with L* and R in a range of 18.1-25.8 and 21.1-31.4%, respectively, were obtained. Doping the CoFe2O4 with calcite or gypsum and bauxite minerals not only enhance its NIR reflectance but would reduce the synthesis cost, thus promoting a widespread use of the NIR-reflective coating for buildings.


CA:P04  The Effect of Varying Quantity and Particle Size of Cristobalite Powders during Synthesizing Cordierite
YI-HSIN LIN, FU-SU YEN, HSING-I HSIANG, Department of Resources Engineering, National Cheng Kung University, Tainan, Taiwan

The effect of increasing chemical activities of cristobalite ingredient used during synthesizing cordierite is examined. The chemical activity was performed by two different ways: One was over adding the amount of cristobalite needed. The other was reducing the particle sizes of cristobalite powders formulated. Results were evaluated by PSD, DTA, XRD, and BET techniques. It is found, although α-cordierite can also be formed at 1100 °C for the samples with cristobalite over adding, lots of β-cordierite was also observed. In this case, the amount of α-cordierite formation can reach 95% at 1350 °C if 3 times of cristobalite powder was formulated. Reducing the particle size of cristobalite can result in similar or even better effects. The α-cordierite was synthesized at even lower temperatures and its yield was up to 97% at 1350 °C.


CA:P05  Fabrication of Translucent Alumina by Vacuum Sintering at Low Temperature
WEN-CHIAO HUANG, FU-SU YEN, CHI-YUEN HUANG, Department of Resources Engineering, National Cheng Kung University, Tainan, Taiwan

Translucent alumina can be fabricated at temperature as low as 1600 °C via improving the packing density of the green compacts. Commercial α-Al2O3 was used as the starting powder. The powder was de-agglomerated and preheated at 800 °C for 1, 6, 12, and 24 to improve particle roundness. Solid slip casting slurries then were prepared using the powders to produce green compacts with packing density as high as 66%. The casts were doped with 500 ppm Mg2+. After drying and surface finishing, the compacts were thermal heated by vacuum sintering at temperatures lower than 1650 °C. It is found that heat treatment at 1600 °C for 2h can be used to achieve translucent alumina with mean grain sizes 8.6 μm and real in-line transmittance 5.18%.


CA:P06  γ+ α- Al2O3 Composite Powders for Fabricating Translucent Aluminas
I-TING LIU, FU-SU YEN, M.C. TOM KUO, Department of Resources Engineering, National Cheng Kung University, Tainan, Taiwan

The possibility of fabricating translucent alumina using mixtures of agglomerated γ-Al2O3 powder ( agglomerate size 250 nm) and α- Al2O3 crystallite powders (crystallite size 180nm) was examined. The mixing ratios were 1:9, 3:7, and 5:5 with chemical purity: Al2O3 99.9%. The α-Al2O3 powders were preheated at 800°C for 12 hrs and then dispersed by ball milling for 6 hrs with addition of Darvan 821A (PAA-NH4, R. T. Vanderbilt, Norwalk, CT, USA) as the dispersant. Slip casting slurries with 50, 38, and 27wt% solid contents then produced to form casts by solid casting. After dried, surface finishing, organic burnout at 550°C for 2.5 hrs, the green products were heat treated at 900°C for 20 mins to improve mechanical strength. Part of the green compacts was doped with 500 ppm Mg2+. Then both the green compacts proceeded to vacuum sintering at 1700°C for 2hr. It is found that mixtures with 1:3 and 3:7 ratios can display optical properties of RIT > 15% and TFT > 80%. The values were raised as the sintered grain sizes increase. Casts with Mg2+ dopant would bring about a reduction in grain size to 1/2 compared to casts without Mg2+ dopant, being less than 25 μm. The appropriate ratio for mixing γ- Al2O3 powder can be less than 4:6.


CA:P07  Particle Size Distribution Variations Driven by Ostwald Ripening Processes
MENG YING LEE, FU SU YEN, Department of Resources Engineering, National Cheng Kung University, Tainan, Taiwan

The growth characteristics of nano-sized a-Al2O3 particles due to the effect of thermal treatment on the crystallite coarsening by Ostwald ripening is investigated in this study. Owing to the tendency of the system toward decreasing in surface free energy, the experimental results showed two distinguishable stages in the particle size evolution: 1.Submicron particles may improve their roundness as heat treatment progresses, exhibiting a particle size distribution reduction tendency. 2. The presence of relatively small-sized particles may act as a donator, resulting in the Ostwald ripening effect which presumably triggers the growth of the coarser particles at the expense of the smaller ones. In this work, a specific temperature represents the powder system in which there exists an upper size limit af. Because of that, the particles may grow up as the calcination temperature increases, leading to the particles with sizes smaller than af to mutual coarsen by Ostwald ripening effects to reach the af size. The af size can approach the maximum one of the raw material, to which the final evolution of the powder system will reach. It is the end of Ostwald ripening. Thus, spherical shape powders with uniform particle size were successfully obtained by Ostwald ripening.


CA:P08  Impact of Pressure in Static and Dynamic Pressing of Ultrafine Plasmochemical ZrO2 (Y)-Al2O3 Powders on Compact Density and Compaction Efficiency during Sintering
T.S. FRANGULYAN, S.A. GHYNGAZOV, National Research Tomsk Polytechnic University, Tomsk, Russia 

Impact of pressure in static and dynamic pressing on densification of plasmochemical ZrO2 (Y)-Al2O3 powder compacts and on compaction kinetics during sintering were investigated. Ultrafine composite powders of the following composition (mass.%): 20 Al2O3-80 (ZrO2- Y2O3), were synthesized using the method of decomposition of a mixture of aqueous solutions of zirconium. Dry uniaxial static pressing and double-action magnetic pulse compaction were employed. The influence of various methods of pretreatment of plasma-chemical oxide powders on the efficiency of their compacting and sintering were investigated. The dilatometry study of the efficiency of various methods for compacting powders of a composite ZrO2-Al2O3 mixture was carried out. It is shown that irrespective of the initial phase state of the ZrO2-Al2O3 powder composite composition, intensification of the sintering process of high-density composite compacts produced by two-sided magnetic-pulse pressing is observed.


CA:P11  Silicon Carbide Ceramics Sintering with Yb2O3-Al2O3 as Additives
YONG JIANG, LANER WU, North Minzu University, Xixia District, Yinchuan, China

SiC ceramics were prepared by hot press with Yb2O3-Al2O3 as sintering additives. The content of additive were 5%, 10%, and 15%(wt) respectively. The molar ratios of Yb2O3/Al2O3 were 8:2, 2:1, 6:4, 1:1, 3:5, 2:8. The phase composition and properties of the sintered bodies were investigated. Experimental results show that the main phases of the samples agree with the phases of the Yb2O3-Al2O3 binary system of Acers-NIST 4.1 Data base. The mechanical properties of the hot-pressed samples show that the samples with 10 wt% additives, 3Yb2O3:2Al2O3 and 2Yb2O3:1Al2O3, attain hardness over 21 Gpa.


CA:P12  Effects of Added Nano Titanium on the Microstructure of Vitrified Bond Diamond Tools
ZUN-KAI JHUANG¹, YUO-TERN TSAI², KUAN-HONG LIN¹, ¹Department of Mechanical Engineering, Tungnan University, New Taipei City, Taiwan; ²Department of Mechanical Engineering, HungKuo Delin University of Technology, New Taipei City, Taiwan

The aims of this study were to investigate the influence of added nano titanium on the microstructure of vitrified bond diamond tools. The specimens were sintered at 710 ℃ for 90 min. The raw powder and sintered specimens were examined using a thermal analyzer, an X-ray diffraction analyzer, a Raman spectrometer analyzer and a scanning electron microscope. The hardness of the sintered specimens was also recorded. TGA analysis of the diamond grits showed a weight loss over 633℃ at atmospheric ambience. Raman spectra analysis showed that an added amount of nano titanium higher than 30vol.% in a vitrified bond diamond tool might contribute to protect the diamond crystal during sintering. XRD analysis observed a rutile TiO2 phase in a sintered specimen with an added amount of 50vol.% nano titanium. The rutile TiO2 phases were unable to dissolve into the vitrified bond, resulting in the expanding of the bond. Therefore, deteriorating the bonding condition between the diamond grits and the matrix, also decreasing the hardness of the vitrified bond.


CA:P14  Thermal Expansion Properties and Structural Analysis of ZrW2-xMoxO8
HUI WEI, SHUNSUKE MIZUTANI, MAKOTO NOGUCHI, KEISHI NISHIO, Department of Materials Science and Technology, Tokyo University of Science, Tokyo, Japan; AKIHISA AIMI, KENJIRO FUJIMOTO, Department of Pure and Applied Chemistry, Tokyo University of Science, Chiba, Japan

Zirconium tungstate (ZrW2O8) is a promising negative thermal expansion (NTE) material that has a three-dimensional isotropic large NTE coefficient (-9 ~ -5×10-6 [K-1]) across a wide range of temperatures (0.3 ~ 1050 [K]). However, ZrW2O8 undergoes an order–disorder phase transition from an acentric (α-phase, space group P 21 3) to a centric (β-phase, space group P a 3 ̅) structure at around 450 K. And the coefficient of thermal expansion (CET) changes from -9 ppm up to 450 K to -5 ppm above 450 K, and this CET changes prevent the use of this material in several devices. It has been reported that the disadvantage is caused by the phase transition temperature, and it can be solved by substituting Mo for W in ZrW2O8. In this study, we prepared pure ZrW2-xMoxO8 bulk ceramics and evaluated NTE properties by using X-ray diffraction with varied temperatures and thermomechanical analysis. We also clarified the effect of substituting Mo in the W sites of ZrW2O8 structures. Rietveld refinement results for the material indicated that the mechanism of NTE was provided by the rigid unit mode model, which is due to the disordering of the W(Mo)O4 tetrahedron in this unique structure.


CA:P17  Peculiarities in Phase Development in the ZnO-stabilized ZrO2 System
K. KUMAR, A. CHOWDHURY, Department of Materials Science & Engineering, Indian Institute of Technology Patna, Bihta, Bihar, India

Zirconia (ZrO2) is one of the technologically most important oxides material due to its applicability in diverse technological fields. Most of its applications need cubic or tetragonal phase of the ZrO2; but pure ZrO2 is obtained in monoclinic form at room temperature. Hence, there is a need to look for suitable dopants for the stabilization of the Cubic/Tetragonal ZrO2 at room temperature. Till date, numerous elements have been successfully tried for the stabilization of the cubic or tetragonal phase of the ZrO2; although, confusion/s is there for the mechanism/s involving such a stabilization process. In this work, we report the use of ZnO as the stabilization of the cubic/tetragonal phase ZrO2; efforts are also laid to investigate its mechanism of structural stabilization. To the best of our knowledge, very few works have been reported for the ZnO-stabilized ZrO2 system. Only 8 mol % of the ZnO was sufficient to retain the stabilized ZrO2 phase. Kinetic studies with thermogravimetry data and other structural characterizations established the importance of the stabilizing cation (Zn2+) for the ZrO2 matrix and is dependent pivotally on process kinetics (rate of heat supply), thermodynamics, (absolute final temperature) and the presence/lack of oxygen in the ambience.


CB:P01  Improvement of Optics, Mechanical Properties and Controlled-release Drug Delivery of Powder Cosmetics
YASUMASA TAKAO, National Institute of Advanced Industrial Science and Technology (AIST), Nagoya, Japan

Through collaboration between industry and government in the Chubu region, we succeeded in blending synthetic seeds, evaluating seeds, cosmetics needs and quickly establishing original products and sensibility studies. By controlling the average inter-surface distance in the liquid and the surface/volume precipitation in the droplet, it was possible to prepare composite particles, hollow granules and drug-encapsulating granules. The microstructure controls enabled to improve the UV shielding property, improve the optical sharpness, and obtain the sustained release rate of the drug. Systematic verification of direct shear testing method and organoleptic evaluation promoted the association between qualitative sensory parameters and physical properties. Standardization of evaluation method has been also acquired.


CB:P02  Study of Mechanical Properties and the Hydrothermal Behavior of Ce-TZP/Al2O3 Sintered by Microwave
L. GIL, M.D. SALVADOR, A. BORRELL, Instituto de Tecnología de Materiales, Universitat Politènica de València, Valencia, Spain; A. FERNANDEZ, Centro de Investigación en Nanomateriales y Nanotecnología (Consejo Superior de Investigaciones Científicas, Universidad de Oviedo, Principado de Asturias), El Entrego, Spain

Biomaterials have been engineered to interact with biological systems for a medical purpose - either a therapeutic (treat, repair or replace a tissue function of the body) or a diagnostic one. They are increasingly used due to increment in life expectancy and improvement in quality of life. Regarding bioceramics, alumina and zirconia are and will be the most ceramics materials used for this purpose, according to a report by Grand View Research. For this reason, an alumina and zirconia composite has been selected. It should be noted that zirconia has been stabilized with Ceria, instead of Yttria, in order to improve some properties as fracture toughness and low temperature degradation. Therefore, the studied composite is zirconia doped with ceria and toughened with alumina (Ce-TZP/Al2O3). On the other hand, Ce-TZP/Al2O3 is sintered by a non-conventional method, microwave technology. The purpose is to obtain highly densified samples by using an eco-friendly method, since dwell time and temperature are lower than those used by conventional sintering, needing less energy resources and processing times. Summarizing, the aim of this study is to sinter Ce-TZP/Al2O3 and assess its properties and its hydrothermal degradation comparing them with those obtained by conventional sintering.


CB:P03  Preparation of Low Frictional Surfaces by Mimicking Firebrat’s Scales
SHUN UEMURA, YUJI HIRAI, MASATSUGU SHIMOMURA, Chitose Institute of Science and Technology, Chitose, Japan

Friction and wear causes a lot of problems in a wide variety of fields, such as energy loss. Thus, lubrications have been used to reduce friction. Recently, friction reductions by microstructures have attracted attention. Therefore, we focused on firebrats, which live in narrow spaces and always their body contacts surroundings. According to SEM observations, and friction force measurements their body surfaces are completely covered by scales with ununiform grooves, and it was suggested that firebrat’s scales may decrease friction forces. Then, in this study, we attempted to prepare the structures for reducing friction force by mimicking firebrat’s ununiform grooves. For preparation of groove structures, wrinkle structures were focused. Polydimethylsiloxane (PDMS) was treated by UV-O3 with photomasks for partial surface wettability change from hydrophobic to hydrophilic. After that, polyvinyl alcohol (PVA) solution was spin coated on the PDMS. In this time, only UV-O3 treated areas of PDMS were coated with PVA solution. After drying PVA solution, PVA solution with different concentration was also spin coated on the PDMS for varying PVA thickness. To compress the PVA/PDMS samples, wrinkle structure with inhomogeneous period, which is similar to firebrat’s scales, was formed.


CB:P04  Evaluations of Barnacle Settlements on Self-assembled Monolayer Surfaces
AI MOMOSE¹, YUTA SEGAWA¹, TAKAYUKI MUROSAKI², YUJI HIRAI¹, YASUYUKI NOGATA³, MASATSUGU SHIMOMURA¹, ¹Chitose Institute of Science and Technology, Bibi, Chitose, Japan; ²Asahikawa Medical University, Asahikawa, Japan; ³Central Research Institute of Electric Power Industry, Abiko, Japan

Barnacles are popular marine sessile organisms, which are a factor of causing problems by attaching to marine structures such as ship hulls. Although tributyltin (TBT) based antifouling paints had been used for preventing the fouling of barnacles, TBT was banned as being toxic to marine organisms. Therefore, the developments of antifouling materials with low environmental impact without toxic are demanded. However, there are a few reports that studied the detail relationship between adhesion of barnacles and surface functional groups of materials. In this study, we attempted to investigate antifouling effects of surface chemistry against barnacles with the precise control of the surface chemical compositions. Self-assembled monolayers (SAMs) which have various terminal functional groups (OH group, COOH group, NH2 group, CF3 group, CH3 group, respectively) were used for controlling the surface chemical compositions of the substrate. After, the barnacle settlement rates on the SAMs preparations ware observed. As a result, there were differences in the barnacle settlement rates and speed on the modified substrate surfaces. In particular, the barnacle settlement rate of the OH group-modified surface is significantly lower than other functional groups.


CB:P05  Ceramic Injection Moulding with 3D-printed Mold Inserts
A.J. MEDESI, D. NÖTZEL, K. PURSCHE, T. HANEMANN, Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany; M. FRANZREB, J. WOHLGEMUTH, Institute for Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany

The powder-based ceramic injection moulding (CIM) is a widely used batch fabrication process. Currently, the fabrication of mold inserts made of metal is the most time consuming factor of conventional moulding processes. Using 3D-printing as rapid tooling technology for the fabrication of plastic mold inserts is a highly attractive approach with the potential to cutting cost and time substantially. However, when 3D-printing technologies were first commercialized, 3D-printed molds were not feasible due to the low heat deflection temperatures of printable plastics. As materials and processes have been improved stronger new printable materials have come on the market and printed molds became a genuine alternative. To address the applicability, reliability and shortcomings of 3D-printed molds, we moulded ceramic microreactor parts using different types of molds. Molds from ABS and PEEK were printed using fused deposition modelling and molds made of two other commercial engineering plastics were printed via Polyjet technology. The usage of these 3D-printed molds was compared to micro-milled molds made out of brass. The topography of the molds as well as of the molded microreactor green parts were investigated with regard to heat deflections, surface roughness and structural accuracy.


CB:P13  Synthesis of ZnWO4 Ceramic Powders by Chemical Method: Correlation between Structural Evolution and Photoluminescent Properties
I. COSTA NOGUEIRA¹, M. SOUSA DA SILVA GONDIM², P. SANTANA LEMOS³, M. DE ASSIS³, E. LONGO³, E.R. LEITE⁴, ¹Department of Physics, Federal University of Amazonas - UFAM, Brazil; ²Federal Institute of Education, Science and Technology of Maranhão - IFMA, Brazil; ³LIEC, Federal University of São Carlos - UFSCar, Brazil; ⁴LNNANO, National Center for Research in Energy and Materials - CNPEM, Brazil

Among the mixed metal oxides, some transition metal tungstates have been studied extensively due to the wide applicability of photoluminescence, electrochemistry, magnetic materials, and photocatalysis. This work aimed to investigate the phase formation as well as the optical properties of zinc tungstate (ZnWO4) ceramic powders, synthesized by a chemical solution process, more specifically, by the Polymeric Precursor Method (MPP). The phase evolution was performed by X-ray diffraction (XRD) with Rietveld refinement, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Raman spectroscopy. The optical properties were characterized by UV-Vis absorption spectroscopy and Photoluminescent measurements. The results showed that in the amorphous state, formed at low temperature (below 550 ºC), the materials show a weak and broad emission centered at 450 nm. On the other hand, the fully crystallized material (single monoclinic phase), prepared at 700 ºC, shows a strong emission, at 640nm. It is important to point out that the ZnWO4 material, processed by other synthetic routes, shows strong PL emission in the region of 500nm. The difference here observed can be associated to the presence of electronic defects that are formed during the genesis of this material.


CB:P14  Structure, Morphology, and Optical Properties of α-Ag2-2xMxWO4 (M = Zn2+, and Cu2+) Solid Solutions Obtained by Coprecipitation and by Femtosecond Laser
P.F.S. PEREIRA, A.F. GOUVEIA, R.C. DE OLIVEIRA, M. ASSIS, E. LONGO, E.C. CORDONCILLO, H. BELTRÁN, G.M. VEGA, CDMF, LIEC, Chemistry Department of the Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil; M. FERRER, Modeling and Molecular Simulations Group, Sao Paulo State University, Bauru, Brazil; R.M.L. BARELLES, J. ANDRÉS, Department of Analytical and Physical Chemistry, University Jaume I (UJI), Castellon, Spain

Metal nanoparticles composed of one or more elements are attracting interest due to their potential properties. The laser irradiation can lead to the formation of periodic surface structures, being an effective technique for changing or modifying materials and a suitable tool for the creation of new materials. The experimental methodology was described in previews work1. DRX patterns data indicated that all the samples obtained experimentally and by laser irradiated presented orthorhombic structures. A slight displacement to higher values of 2 θ was observed for samples irradiated with laser. MR and FT-IR spectroscopies confirmed that all vibrational modes are characteristic of the orthorhombic structure. Some vibrational modes were not observed on the irradiated samples. FE-SEM images revealed that the incorporation of Zn2+, and Cu2+ in the α-Ag2WO4 structure affected the shape and size of the microcrystals and caused a shift in the electronic and optical properties. HR-TEM image of the sample obtained after laser irradiation showed there was a release of metallic nanoparticles.
1P.F.S. Pereira, C.C. Santos, A.F. Gouveia, M.M. Ferrer, I.M. Pinatti, G. Botelho, J.R. Sambrano, I.L.V. Rosa, J. Andrés, and E. Longo. Inorg. Chem., 2017, 56, 7360-7372.


CB:P19  Flash Sintering of ZrO2 / Al2O3 Composites
C.L. OJAIMI, J.A. FERREIRA, USP, Pirassununga, SP, Brazil; A.S.A. CHINELATTO, A.L. CHINELATTO, UEPG, Ponta Grossa, PR, Brazil; E.M.J.A. PALLONE, USP, Pirassununga, SP, Brazil

Unlike conventional sintering that occurs at high temperature and for a few hours, in flash sintering, consolidation occurs at an extremely high densification rate at a lower sintering temperature, what has been gaining highlight in the area of ceramic materials. These results are obtained by applying an electric field in a specimen using a pair of electrodes, while heating occurs conventionally. In this study was analyzed the flash sintering of ZrO2 and Al2O3 composite, varying the percentage of the components, in order to understand the magnitude of the electric field in relation to the sintering temperature reached. For this, the specimens of compositions 75% vol ZrO2 - 25% Al2O3, 50% vol ZrO2 - 50% vol Al2O3 and 25% vol ZrO2 and 75% Al2O3, were submitted to different electric fields and the results were compared with samples sintered conventionally. The results showed that higher magnitude electric fields promoted the flash sintering at a lower temperature, being this temperature well below the conventional sintering temperature of these composites. As for the compositions, it was found that the higher the amount of alumina, the greater the magnitude of the electric field needed to promote the flash sintering.


CC:P01  Boron Carbide/Graphene Platelet Ceramics with Improved Fracture Toughness, Functional and Tribological Properties
R. SEDLAK¹, A. KOVALCIKOVA¹, J. BALKO¹, P. RUTKOWSKI², A. DUBIEL³, E. MUDRA¹, V. GIRMAN⁴, J. DUSZA¹, ¹Institute of Materials Research, Slovak Academy of Sciences, Division of Ceramic and Non-Metallic Systems, Košice, Slovak Republic; ²AGH University of Science and Technology in Krakow, Faculty of Materials Science and Ceramics, Krakow, Poland; ³The Institute of Advanced Manufacturing Technology, Krakow, Poland; ⁴Pavol Jozef Šafárik University in Košice, Faculty of Science, Institute of Physics, Department of Condensed Matter Physics, Košice, Slovak Republic

Boron carbide/graphene platelet (B₄C/GPLs) composites have been prepared with the addition of different weight percent of GPLs by hot-press processing technology at 2100 °C in argon. The influence of the GPLs addition on microstructure development, fracture toughness, electrical conductivity and tribological properties was investigated. The microstructure was studied by SEM, TEM, HRTEM, XRD and Raman spectroscopy. SEVNB method was used for fracture toughness and four-point Van der Pauw method for electrical conductivity measurement. Almost fully dense B₄C/GPLs composites have been prepared with lower wt.% of GPLs additives with relatively homogeneously distributed platelets in the matrix. With increasing amount of GPLs additives, the fracture toughness increased due to the activated toughening mechanisms in the form of crack deflection, crack bridging, crack branching and graphene sheet pull-out. The highest fracture toughness of 4.48 MPa.m^1/2 was achieved at 10 wt.% of GPLs addition, which was ~50 % higher than the K_IC value of reference material. The electrical conductivity increased with GPLs addition with percolation threshold between 6–6.5 wt.% of GPLs and reached the maximum values at 8 wt.% GPLs addition. A significant improvement of electrical conductivity around two orders of magnitude up to 1526 S/m in the perpendicular direction and to 872 S/m in parallel direction was noticed. The friction and wear behaviour of B₄C/GPLs composites have been investigated using the ball-on-flat technique with SiC ball under dry sliding conditions at room temperature. The coefficient of friction for composites were similar, however the wear rate significantly decreased ~77 % in the case of B₄C+10 wt.% GPLs when compared to reference material at a load of 5 N, and ~60 % at a load of 50 N. Wear resistance increased with increasing GPLs content in regards to the present graphene platelets, which during the wear test pulled-out from the matrix, exfoliated and created a wear protecting graphene-silicon based tribofilm. For revealing and observation of the wear damages under the worn surfaces, focused ion beam (FIB) technique was used for the preparation of the cross section of wear tracks.
Acknowledgements: The authors gratefully acknowledge the financial support from Journal of ECerS Trust (Contract 2016116) and from projects: APVV-15-0469, VEGA 2/0163/16, VEGA 2/0189/15, VEGA 2/0130/17, MVTS 7RP ERA.NET-GRACE, ITMS 26220220105 and FNP – No. POWROTY/2016-1/3.


CC:P03  Corrosion Protection of Ceramics Using Carbon-silver Film 
A.A. VIEIRA¹, L.A. MANFROI¹, M.A. RAMIREZ¹, P.A. RADI^1,2, A.C. SENE¹, S.F. SANTOS³, J.V. SOUZA³, L. VIEIRA^1,2, ¹University of Paraiba Valley-UNIVAP/IP&D, São José dos Campos, SP-Brazil; ²Aeronautics Institute of Technology, ITA / LPP, São José dos Campos, SP-Brazil; ³São Paulo State University (UNESP), School of Engineering, Department of Materials and Technology, Guaratinguetá, SP-Brazil

In oxidation studies, most of the oxidation properties are determined by the oxide film caused by chemical reaction. Therefore ceramic materials require a protective oxide with a low oxygen diffusivity. The leading protective oxides for ceramics are silica SiO₂ and alumina Al₂O₃. Other protective oxides, such as Ag₂O impregnated in carbon coatings may be acceptable for applications where a surface passivation is required avoiding oxygen diffusivity. The oxygen diffusivity in Al₂O₃ ceramic base material can reduce mechanical resistance increasing wear. In this work carbon and silver mixture as a protective coating was deposited by plasma enhanced chemical vapor deposition (PECVD) and also by laser cladding in Al₂O₃ base ceramic material. Each technique was used to produce one film with different chemical structure. The carbon-Silver films produced by PECVD and by laser cladding were used to run out tribological studies as a protective coating for ceramic base material (Al₂O₃). The Al₂O₃ with and without  carbon-Silver film were tested under atomic oxygen bombardment. The oxygen bombardment was run out in oxygen discharge using a RIE (Reative Ion Etching) reactor. Results showed that addition of Carbon-Silver film decreased corrosion life time by 75% when compared with bare Al₂O₃.


CC:P04  Graphene Nanoplatelets Reinforced Plasma Sprayed Alumina-titania Coating with Improved Corrosion and Wear Resistances
B. MUKHERJEE, R. SINGH, A. ISLAM, A. KUMAR KESHRI, Department of Materials Science and Engineering, Indian Institute of Technology Patna Bihta, Patna, Bihar, India

Alumina- 13 wt. % titania coating containing various amounts of graphene nanoplatelets (GNPs) were deposited by atmospheric plasma spray technique over steel substrates. Raman spectroscopy shows the GNPs to survive the process albeit with only a marginal increase in the density of defects in the graphitic lattice. The effects of GNPs on the microstructure were studied and corrosion resistance of the coatings was investigated under 3.5% NaCl solution. The corrosion resistance was found to be significantly improved after the incorporation of GNP in the coating when compared to that of monolithic coating. The coefficients of friction of the GNP reinforced coatings were approximately two times lower in comparison to the monolithic coating due to the lubricating effect of GNP during sliding.


CC:P06  Support with Bactericide Coating for Curative Accomplishment and Hygiene on Inferior Memberst
R. CELIA¹, T. BAESSO¹, A.C. SENE¹, L.A. MANFROI¹, A.A. VIEIRA¹, P. A. RADI^1,2, M.A. RAMIREZ¹, N.S. DA SILVA¹, L.VIEIRA^1,2, ¹University of Paraiba Valley- UNIVAP/ IP&D, São José dos Campos, SP-Brazil; ²Aeronautics Institute of Technology, ITA / LPP, São José dos Campos, SP-Brazil

Hospital infections and antifungals resistance is a public problem health and has been growing, From last decade in Brazil, the hospital infections was responsible for 60% of patients death. The purpose of this work was to develop a project for a support model to proceed with wound dressing and hygiene in inferior members (legs and feet), being demountable, lightweight, easy to clean, disinfect and able to supply comfort for the patient and to support the nurses technique execution. The prototype was manufactured in stainless steel 316L covered with DLC films. The 316L is commercially material used for the construction of hospital equipment. The prototype is in testing phase. It is believed that the construction of support will contribute effectively to the improvement of nursing care to the patient / client, facilitating manipulation by the nursing staff and / or other healthcare professionals.The bactericide test results using Pseudomonas aeruginosa and Staphylococcus aureus on 316L will be presented.


CD:P02  Theoretical Prediction and Experimental Determination of the Phase Transformation Sequence in Al-Ni Multilayer Termite Structures
D.G. GROMOV, E.A. LEBEDEV, L.I. SOROKINA, National Research University of Electronic Technology (MIET), Moscow, Zelenograd, Russia; A.YU. TRIFONOV, Lukin Research Institute of Physical Problems, Zelenograd, Russia

Multilayer termite materials are actively used for various surfaces joining in micro- and nanoelectronics and as local heat sources for various MEMS and NEMS devices. The heat release intensity in such materials determined by their composition and structural parameters (bilayer and total thicknesses). However, a comprehensive study and a clear understanding of the processes that result in energy release of and the factors that influence them are necessary for effective optimization and improvement of the multilayer termite materials characteristics. Over the past three decades, various theoretical and experimental approaches have been developed and are being used to determine the influence of the components ratio in multilayered thermite structures on the phase transformation sequence during their heating. Nevertheless, the results obtained often contradict each other and do not give an unambiguous answer. In the present work, a theoretical prediction of the phase transformation sequence in a multilayer Al-Ni structures was carried out using an original thermodynamic model that takes into account the components ratio in the initial material, as well as the results of the experimental verification of the prediction using the XRD method.


CD:P03  Investigation of Wave Combustion Processes in Multilayer Al-Ni Structures Formed on the Surface of Three-dimensional Silicon Structures
E.A. LEBEDEV, D.G. GROMOV, National Research University of Electronic Technology (MIET), Moscow, Zelenograd, Russia; E.P. KITSYUK, YU.P. SHAMAN, Science-Manufacturing Center “Technological Centre”, Moscow, Zelenograd, Russia; A.A. PAVLOV, Russian Academy of Sciences, Department of Development and Research of Micro- and Nanosystems, Moscow, Russia

Since the 60s high-energy chemical reactions between substances that occur in the wave combustion mode are used for self-propagating high-temperature synthesis of composite materials. At present, a relatively new method of surfaces joining using multilayer termite materials, in which similar processes occur after primary initiation, has become widespread. The use of traditional methods and processes (for example, the method of magnetron sputtering or electron beam evaporation) of microelectronics for their formation is one of the main advantages of such structures. This fact not only makes it possible to control the thicknesses of individual layers to within a few nanometers, but also to create a complex topological patterns. All this opens up wide possibilities for the use of multilayer structures for the precise assembly and packaging of miniature electronic devices, incl. MEMS. In this paper, we studied the features of the formation and combustion of Al-Ni multilayer structures on the surface of three-dimensional "meander" type structures with a complex topology formed on the surface of silicon substrates. The results of the velocity of the combustion front propagation measurements in structures formed on substrates surface and in the form of foils are presented.


CE:P03  Effect of Electrochemically Induced Phase Transformation on the Electrical and Mechanical Properties of Yttria-stabilized Zirconia
KUK-JIN HWANG, TAE HO SHIN, Korea Institute of Ceramic Engineering and Technology, Gyeongsangnam-do, South Korea; HEESOO LEE, Pusan National University, Geumjeong-gu, Busan, South Korea

Yttria-stabilized zirconia (YSZ) has been used as an electrolyte in solid oxide fuel cells (SOFCs) due to its ionic conductivity and chemical stability. The phase stability and phase transformation of yttria-stabilized zirconia are critical to performance as SOFCs electrolyte. Yttrium additions in ZrO2 system induces either tetragonal or cubic phase stabilization that depends on the yttrium content. In this study, two different composites of commercial 6YSZ, 8YSZ powders are investigated. The Raman scattering technique and X-ray diffraction were used to analyze the phase change after the electrochemical cycling. The electrical properties studied by impedance spectroscopy as a function of temperature. Biaxial flexural strength and fracture toughness of samples were measured by Vickers micro hardness indentation methods. The results suggested that the changes of conductivity and flexural strength on yttria-stabilized zirconia was caused by the phase transition.


CE:P04  ZnO Nanorods Array as Electrode for Supercapacitors and Photo-supercapacitors
D. SOLIS¹, A. BRITO¹, E. NAVARRETE-ASTORGA¹, E.A. DALCHIELE², D. LEINEN¹, J.R. RAMOS-BARRADO¹, F. MARTIN¹, ¹Laboratorio de Materiales y Superficies. Departamentos de Física Aplicada & Ingeniería Química, Universidad de Málaga, Málaga, Spain; ²Instituto de Física, Facultad de Ingeniería, Montevideo, Uruguay

ZnO is a wide bandgap semiconductor that has attracted increasing interest. Nanorods when forming arrays (NRAs) are very interesting, and specifically when NRs are vertically arranged with respect to the substrate. The ZnO nanorods exhibit fewer defects than ZnO thin-films, and present a pseudo-one dimensional structure with an enhanced surface-to-volume ratio and confinement effects. High power density, high reliability, and fast charge-discharge rate are characteristics of supercapacitors (SCs) that have converted them as a feasible alternative or complement to batteries. Hybrid electric vehicles, uninterruptable power supplies, memory back-up systems are possible applications of the SCs. Two electrodes and an ionic conductor electrolyte form SCs. On the other hand, the possibility to join energy generation and storing is very attractive. Photo-Supercapacitors (PSCs) are promising devices that meet these requirements. Both, SCs and PSCs have similar requirements on electrolytes. ZnO nanorods have been grown on transparent conductors like ITO, FTO or GIZO, and coated with nanoparticles of metal sulphides as sensitizers, and used as electrodes for SCs and PSCs.


CE:P05  A Novel Ultrafast Inorganic Absorbent for Micropollutants in Aquatic Systems
YAN XING, JING CHENG, WEI PAN, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, P.R. China

Our "Blue Planet" is facing increasingly severe environmental issues caused by water contamination with micropollutants. Fast, reusable and ecofriendly absorbents are critical for the wastewater purification technology which is of great importance to alleviate water resources shortage and protect public health. Here, we have fabricated a novel Ni/La2O3 nanofibers that can rapidly remove multiple micropollutants that detected in various aquatic environments in 10s with the greatest absorption rate constant so far. In addition, the nanofibers can be recycled several times by a soft wash procedure under ambient temperature with no obvious performance decline. We also applied this nanofibers in simulated industrial flow-through tests. It is well indicated from the results that the Ni/La2O3 nanofibers are prospective for real water treatment application.


CE:P08  Preparation of Polymethylsilsesquioxane Aerogels with Improved Strength Using Strong Base Catalyst
RYOTA UEOKA, KAZUYOSHI KANAMORI, KAZUKI NAKANISHI, Department of Chemistry, Graduate School of Science, Kyoto University, Japan

Silica aerogels have unique properties, such as high transparency, low bulk density and low thermal conductivity. However, serious mechanical friability and high production cost have made their versatile applications difficult. Organic-inorganic hybridization has been investigated to improve these serious drawbacks. Polymethylsilsesquioxane (PMSQ) aerogels, obtained from methyltrimethoxysilane (MTMS) through a two-step sol-gel process based on weak acid and weak base catalysts, show high transparency, low bulk density, and high strength and volume recovery against compressive deformations. However, there is room for improvements in such as the time-consuming washing process and incomplete polymerization. In the present study, mechanically stronger PMSQ aerogels have been prepared through a simplified washing process by employing liquid surfactant as the solvent and an organic strong base as the catalyst. The obtained aerogels show no residual strains against 10 cycles of 50 % uniaxial compressive deformations.


CE:P09  New Ceramic Nanoparticle-reinforced Polyacrylates Fabricated by 3D Inkjet Printing and UV-curing
D. GRAF, T. HANEMANN, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Baden-Württemberg, Germany; S. BURCHARD, University of Freiburg, Freiburg, Baden-Württemberg, Germany

Aluminum oxide nanoparticles were introduced into an UV curable ink for 3D inkjet printing. Thereby, it was possible to adjust the mechanical properties of the composite after it was cured. The ceramic was grinded and homogenized in UV curable monomers. Due to the increased surface of the fillers a stabilizer was used to prevent agglomeration. For the characterization of the pure ceramic thermogravimetric analysis (TGA) was utilized. To analyze the particle size distribution (PSD) in the dispersion dynamic light scattering measurements have been done. For the assessment of the mechanical properties tensile specimens have been produced via layer-by-layer curing and respective tests have been conducted. Furthermore, the viscosity of the ink was measured, and inkjet printing with a commercial device have been undertaken. The TGA analysis of the nanoparticles hinted at the presence of water and hydroxide groups. For the suspension agglomeration could be seen to a certain extent in the PSD, despite stabilizer addition. Following tensile tests have shown the possibility to adjust the Young’s modulus, tensile strength, and elongation at break of the solidified composites. Moreover, after adjusting the viscosity, printing tests were successfully conducted.


CE:P10  Maximizing Thermoelectric Performance of AgPbmSbTem+2 by Optimizing Spark Plasma Sintering Temperature
JUN PEI¹, BO-PING ZHANG¹, JING-FENG LI², DOU-DOU LIANG¹, ¹The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China; ²State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China

AgPbmSbTem+2 (abbreviation as LAST) is a promising thermoelectric material based on PbTe for mid-temperature applications. The electrical and thermal transport properties of LAST alloys are greatly affected by the formation of nanostructured precipitation depending on the processing conditions, especially for spark plasma sintering (SPS) combined with mechanical alloying (MA). This study was focused on the optimization of SPS temperature (TSPS) and found that its variation in a narrow range (100 K) leads to apparent differences of thermoelectric performances. The sample sintered at an optimized temperature (TSPS=923 K) shows a low κtotal (0.829 Wm-1K-1) and a high PF (14.9 Wm-1K-2), which is mainly attributed to the nanoscale composition segregation of Ag and Sb. The highest ZT value of 1.28 at 773 K was obtained when TSPS=923 K, along with the highest ZTeng value of 0.26 and the corresponding ηmax value of 5.8% at the range of 323 K (Tcold)-773 K (Thot), which were increased almost twice by the optimization of sintering temperature.


CE:P11  Preparation of Monolithic Porous Mg-based MOFs via Sol-gel and Solvothermal Processes
SEONGJU JEON, X. LU, K. KANAMORI, K. NAKANISHI, Department of Chemistry, Graduate School of Science, Kyoto University, Japan

Magnesium oxide (MgO) and Mg-based MOFs (Metal-Organic Frameworks) are remarkable materials in carbon capture and storage (CCS) technology, because of their high CO2 capture capacity. In order for practical applications, MOFs in a monolithic form with external porosity are desired to enhance the accessibility of the external substances to adsorption sites and material handling. In the present research, Mg-based MOFs with controlled porosity in the monolithic form have been studied. First, Mg(OH)2 porous monoliths have been prepared via sol-gel process, which was then processed in a solvothermal condition with 1,3,5-benzenetricarboxylic acid (H3btc) in order to allow a pseudomorphic transformation to Mg3(btc)2 MOF to occur. The obtained materials were characterized by powder X-ray diffraction and thermogravimetric analysis to confirm the progress of the transformation to MOF. In addition, MgO-based monoliths have been obtained by heat treatments of the Mg(OH)2 monoliths. Specific surface area and CO2 adsorption properties of the MOF and MgO-based monoliths have been investigated to examine differences in the CO2 capture performance.


CE:P12  CuxS Superionic Compounds: Electronic Structure and Thermoelectric Performance Enhancement
BO-PING ZHANG¹, LI-JUN ZHENG^{1, 2}, HE-ZHANG LI¹, JUN PEI¹, JIA-BING YU³, ¹The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China; ²School of High Temperature Materials and Magnesite Resources Engineering, University of Science and Technology Liaoning, Anshan, China; ³Department of Materials Science and Engineering, Peking University, Beijing, China

In the present work, we have investigated the effect of Cu content (x) on the phase structure and thermoelectric transport properties of CuxS (x=1.92, 1.94, 1.98) bulks fabricated by combining mechanical alloying and spark plasma sintering. From density functional theory calculations of the valence band energy levels, we hypothesized that favorable valence band alignments accelerate electrical transport and can be achieved by optimizing the molar ratio of Cu1.96S to Cu2S. Experimentally, the sample with x=1.92 showed an improved electrical conductivity 538.7 Scm-1 at 623 K and retained a good Seebeck coefficient, synergistically leading to a broad, high power factor ranging from 105.9 to 900.3 µWm-1K-2. The highly-disturbed Cu ions give CuxS compounds an intrinsically low lattice thermal conductivity (~0.5 Wm-1K-1), which endows a high ZT of 1.23 as x=1.94 to this otherwise simple semiconductor. The results indicate that low-cost and non-toxic CuxS superionic compounds are promising thermoelectric materials.


CG:P01  Microstructure Characterization of Ti-Al-C MAX Phases Obtained by SPS
S. SIGNE GOUMWE, M. GONON, J.-P. ERAUW, M. DEMUYNCK, P. AUBRY, Materials Institut of University of Mons, Mons, Belgium

« MAX phases » are a very important and interesting class of layered ternary carbides and nitrides, thanks to their unusual properties that combine both those of metals and ceramics. Among all MAX phases synthetized nowadays, Ti2AlC and Ti3AlC2 are distinguishable by their exceptional properties: they are the most lightweight and oxidation resistant ternary carbides [1]. This work is part of a project that studies the influence of experimental conditions using SPS (Spark Plasma Sintering) to synthesize Ti2AlC/Ti3AlC2 MAX phases, starting with powder mixtures of TiC/Al/C. To reach this goal, it is important to be able to provide complete and reliable characterization of phases and microstructures of the obtained products, both bulk and powders. To this end, the possibility to characterize preferential orientation, microstrains, shape and size of crystallites using XRD and Rietveld analysis has been studied. The effects of (00l) preferential orientation phenomenon related to nano-lamellar structure on the reliability of quantitative analysis have been particularly evaluated.


CG:P02  Characterization and Simulation of Filler Element Incorporation in the Ti2AlC Ceramics
CHENGJIE LU^{1, 2}, J. ZHANG¹, G. HUG², ¹Harbin Institute of Technology, Harbin, China; ²LEM ONERA-CNRS, France

The nanolaminate ternary ceramics Mn+1AXn can be described as the stacking of octahedral Mn+1Xn layers interleaved with layers of pure A. The unique structure endows these compounds with distinctive combination of metallic and ceramic properties. As a fascinating member, Ti2AlC is of particular interest since the compound has the lowest density and the best oxidation resistance in the family of MAX phases. To promote the practical applications, several efforts on the brazing of the Ti2AlC ceramics have been performed by our research group. Afterwards, the brazing mechanisms are revealed by microstructure characterization, and the function mechanisms of different brazing filler elements on the Ti2AlC substrate are illustrated using ab initio method. The results suggest the Ti2AlC structure is tolerate of vacancies, especially at high temperature. Then, the substitution behaviour of the filler elements on the vacancy site is spontaneous, because of the lower formation energy of the reactants. However, with the increasing content of substitution atoms, the defective structure tends to be unstable in the vibrational aspect, also might decompose due to the lower Gibbs energy of the competing phases.


CG:P04  Rapid Preparation and Characterization of 2D Ti3C2 Nanocrystals
SHUJUN HU, S.B. LI, J.P. JIANG, J. ZHANG, J. LIU, Center of Materials Science and Engineering, School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, Beijing, China

Since graphene was discovered in 2004, two dimensional (2D) materials with excellent properties have attracted much attention. MXenes are a new family of 2D materials. MXenes are produced by selective etching the A layer in MAX phases. MXenes have potential applications in hydrogen storage, electrochemistry, catalysis and other fields due to their unique layered structure. So far, several methods have been adopted to prepare MXenes but with a long period of time (more than ten or even tens of hours). In this work, the influence of etching time, reacting temperature and stirring mode on the formation of a Ti3C2 MXene has been investigated. After optimization of processing conditions, the Ti3C2 MXene was achieved with only 2 h. The Ti3C2 powders were characterized. This method can be used to prepare other MXenes with a short time. The thermal stability of Ti3C2 was also studied in vacuum atmosphere. The as-synthesized Ti3C2 can be stable up to 800 °C in vacuum. Ti3C2 was completely transformed to TiC as the temperature increased to 900 °C.


CH:P01  Damage Detection of Multilayer Coating System by Digital Image Correlation at High Temperature
RYO INOUE, Y. KOGO, Tokyo University of Science, Tokyo, Japan; H. KAKISAWA, National Institute for Materials Science (NIMS) Ibaraki, Japan

A mullite/Si multilayer coating on a SiC substrate was fabricated using an atmospheric plasma spraying (APS) process. Damage evolution of the surface protective mullite layer was examined using a high-temperature observation system (HTOS). In-plane surface strain distributions were also measured using the digital image correlation (DIC) method. The experimental results showed that mud cracks nucleated in the mullite layer during heating, primarily due to shrinkage of the mullite by crystallization. The cracking event was detectable by mapping the maximum principal strain distribution. Our findings demonstrate the effectiveness of HTOS and DIC as tools for investigating the degradation mechanisms of thick coatings at high temperatures.


CH:P03  Oxidation Behavior of Ytterbium Silicides
TOSHIHISA MIYAZAKI, S. USAMI, R. INOUE, Y. KOGO, Tokyo University of Science, Tokyo, Japan

EBC system is developed to protect SiC/SiC composite in high temperature and steam environment. Bond coat (BC) provides good adhesion to the SiC/SiC substrate, and can also function as a sacrificial oxidation layer. Si is considered as most effective material, but it is not applicable to next generation gas turbine engine operating above 1450 ℃ because melting point of Si is 1414 ℃. In addition, silica forms within Si by oxidation. Formation of SiO2 leads to severe cracking because of shrinkage during transformation. The objective of this study is to develop new BC materials in EBC system for operation above melting point of Si. In the present study. Ytterbium silicides are synthesized by heat treatment in a quartz ampoule using bulk ytterbium and powder silicon as starting materials. Then, sample was crushed in an argon atmosphere and powder compact was sintered by spark plasma sintering. XRD profile of crushed powder confirms that we successfully synthesize Yb5Si3 (Melting point: 1630 ℃). Sintered compact is obtained without formation of pores and cracks although we identify small amount of oxidation products (Si and Yb2O3). In this presentation, oxidation mechanisms of Yb5Si3 in air and steam at high temperature will be discussed based on experimental results.


CH:P04  Silicon Carbide Based Coatings for Graphite to Increase Oxidation Resistance
E. SALERNITANO, F. BEZZI, S. GRILLI, F. BURGIO, P. FABBRI, G. MAGNANI, ENEA SSPT-PROMAS-TEMAF, Laboratory of Materials Technologies Faenza: Faenza (RA), Italy

Graphite is an attractive engineering material for high temperature applications due to its high tensile strength and modulus, excellent thermal shock resistance and low density, but its application is limited by the low oxidation resistance. SiC/SiC-MoSi2 protective coatings for graphite were deposited by a two-step pack cementation method on substrates of graphite to increase the oxidation resistance. The effects of the pack formulation, composed of carbon and silicon powders, density of the substrate and cementation thermal treatments were investigated. The operating conditions were optimized to obtain a homogeneous, bonded and crack-free layer in the first step. In the second step it was used as pack a mixture of carbon, silicon and molybdenum disilicide powders and different thermal treatments were tested in order to obtain a final SiC/SiC-MoSi2 coated graphite with increased oxidation resistance. The behaviour of SiC/SiC-MoSi2 coated graphite was studied by thermogravimetric analysis in flowing air determining an increase of the oxidation resistance. The coated graphite samples were characterized, before and after oxidation, to identify crystalline phases by X-ray diffractometry and observe the cross-section and surface morphology by the scanning electron microscope.


CH:P05  Use of Non-destructive Techniques for the Determination of Failure in Thermal Barrier Coatings
L. NAVARRO¹, P. CARPIO¹, M.D. SALVADOR¹, R. MORENO², ¹Instituto de Tecnología de Materiales (ITM), Universitat Politècnica de València (UPV), Valencia, Spain; ²Instituto de Cerámica y Vidrio (ICV), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain

Thermal barrier coatings (TBC) is one of the most important coating in the industry, because plays an important role protecting metallic superalloy, from being oxidized, corroded and worn. This protection allows gas turbines to operate at high temperature. TBC is composed of yttria-stabilized zirconia ceramic top layer (YSZ) and bond layer that act as a stress attenuator, due to the difference of coefficients of thermal expansion between YSZ and superalloy. The characteristic of TBCs, besides intrinsic properties of material depends on the microstructure of coatings, which depends on the deposition technique which was suspension plasma spraying. Due to the hard working conditions, TBC has limited life time; the main of this work is present non-destructive methods to determine the “damage accumulation” of TBC. Non-destructive methods such an acoustic emission (AE) and infrared thermography (IR) have been used successfully to monitor the quality of coating. AE technique and three-point bending test is used to monitor the cracking behaviour and fracture process of TBC, the objective is find some relationship between the failure modes of the TBC and acoustic emission parameters. IR and thermal fatigue is used to monitor the dynamic behaviour to determine the fatigue limit.


CH:P07  Application of Tungsten Oxide Thin Films for Active Gases Detection
M.V. CHUPRIN, O.M. IVANOVA, S.A. KRUTOVERTSEV, L.S. KRUTOVERTSEVA, A.E. TARASOVA, CJSC “Ecological sensors and systems”, Zelenograd, Moscow, Russia

Gas sensors based on thin films are preferred for their mass, power consumption, and obviously cost characteristics. Oxides of transitional metals possess a high sensitivity. They have cations of metals, whose d-shells are not filled completely. Application of group technology allows creating a sensitive element with smallest size (parts of millimeter). The aim of this work is to analyze characteristics of WO3 films, deposited on substrate by two methods: thermal sputtering in vacuum and thick film technology. The investigations were carried out under the sensor thermal stabilization conditions in the range 50 – 450 °C. All films are mostly sensitive to the relative humidity when it is less than 30% at temperatures which are less than 200 °C. Both type of films showed maximal sensitivity at 150-200 °C to NO2 micro concentrations. Resistance of thick films increased five times to NO2 concentration of 10 ppb. Films’ sensitivity to H2S micro concentrations was investigated. The maximum resistance change to H2S of 5 ppb was observed at 300-350 °C. The sensor film characteristics can be purposely changed by varying conditions of film formation and by varying film temperature.


CH:P11  Wear Resistance of Plasma Sprayed Graphene Nanoplatelets Reinforced Alumina Coating in Dry and Wet Environment
O.S. ASIQ RAHMAN, S. PRIYADERSHINI, A. KUMAR KESHRI, Materials Science and Engineering, Indian Institute of Technology Patna, Patna, Bihar, India

Graphene nanoplatelets (GNPs) reinforced alumina coating has been fabricated on a steel substrate using atmospheric plasma spray technique. The influence of GNPs addition on microstructure, mechanical and tribological properties was investigated. Incorporation of GNPs in alumina matrix leads to the exceptional improvement of densification from ~91% to ~96%. Increase in densification was attributed to the incorporation of higher thermal conductive GNPs (∼5000 W/mK) in the alumina matrix leads to the higher degree melting of the alumina splats. Increased densification directly translates to the excellent improvement of hardness, elastic modulus and fracture toughness of the coating. According to Evan’s and Marshall’s empirical equation, the high hardness combined with high fracture toughness leads to the improved wear resistance of the coatings. In order to evaluate the wear resistance of the coatings on both dry and wet environment, ball-on-disk tribometer of load 30 N was carried out. Role of GNPs on both dry and wet wear behaviour was discussed in detail.


CI:P01  Preparation and Characterization of Transparent SiO2 Sponges for Water Treatment
F. LOEFFLER, E.C. BUCHARSKY, K.G. SCHELL, M.J. HOFFMANN, Institute for Applied Materials - Ceramic Materials and Technologies, Karlsruhe Institute of Technology, Germany

Transparent open-pored glass structures have the ability to distribute light in the surrounding environment. In addition, gaseous materials and liquids can pass through the pores. Due to these properties transparent open-pored sponges are of high interest for photocatalytic based waste water treatment devices. They have the potential to enhance the efficiency of photocatalytic materials due to a more efficient light distribution. Amorphous silica, which has a high transparency and is chemical as well as mechanical stable, is supposed to be a useful material for this application. The research topic of this work is the development of transparent sponges in a wide range of pore sizes. Glass sponges can be produced by using the polymer replica technique. A polymer is coated with a water based suspension containing SiO2 particles. By a thermal treatment process the polymer is removed and the SiO2 remains as a green body in the former sponge shape. After a sintering step a transparent SiO2 sponge with pores in the range of millimeters is produced. Further techniques have the potential to create sponges with defined pore structures. By a preparation of an organic suspension which can be cured with light, stereo lithography can be used to 3D print sponges with pores in a micrometer range.


CI:P02  Fabrication of Functional Porous Ceramics by In-situ Solidification Process for Mitigating Environmental Issues
TAKASHI SHIRAI, YUNZI XIN, JEONG SOO HONG, Nagoya Institute of Technology, Nagoya, Japan

Porous ceramics are very widely used in many industrial applications, such as filters, catalyst for chemical industries and automobiles, light weight structural materials, biomaterials and so on. Among various processing technologies to fabricate porous ceramics, gel casting has gained much attention due to easy processing and easy to develop any complicated shape. We have successfully developed several materials with tailored pore structure such as ceramic filter, super-porous construction materials, and electrically conductive ceramics.  Controlling the pore shape and size by gelcasting of slurry involving bubbles provides an effective and cheap way in fabricating porous ceramics.  Various types of foamed slurries can be in-situ solidified by polymerization of monomer.  One of these is cordierite ceramic filter which is fabricated by conventional gelcasting in nitrogen atmosphere.  In an attempt to reduce the industrial and mining wastes, we have fabricated super-porous construction materials with the aid of natural gelformer.  The use of Japanese gelatin, as a gelling agent, enabled the solidification of mechanically foamed slurry under ambient atmosphere.  This process also allows a development of endless recycling system of waste resources to produce ceramic materials with characteristics such as sound absorbance, super lightness, high insulation and easiness in machining.


CI:P03  Synthesis and Characterization of Ta2O5 Monolith with Co-continuous Macroporous Structure via Sol-gel Routea
NAOTO MOCHIZUKI, K. KANAMORI, K. NAKANISHI, Department of Chemistry, Graduate School of Science, Kyoto University, Japan

Tantalum oxide has been attracting considerable attentions, because of its potential uses in various field of applications such as catalyst and electrode. In applications as a catalyst, the co-continuous macroporous structure is highly desirable because the interconnected macroporous channel facilitates the material transport to reaction sites. While porous tantalum oxide has been known, monolithic tantalum oxide with the co-continuous macroporous structure has not been reported. In this research, co-continuous macroporous Ta2O5 monoliths derived from ionic precursors have been successfully prepared via the sol-gel route accompanied by phase separation in the presence of polyethylene oxide (PEO), polyvinylpyrrolidone (PVP) and propylene oxide (PO). Appropriate amounts of PEO and PVP as phase-separation inducers and PO as a gelation mediator allow the formation of xerogels with the co-continuous macroporous structure and monolithic shape. We will discuss characteristics of these materials, such as the pore size distribution, BET specific surface area and crystalline phases.


CI:P04  Multiscale Controlled Fe2O3 Monoliths via Polymerization-Induced Phase Separation
YOSUKE HARA, K. KANAMORI, K. NAKANISHI, Department of Chemistry, Graduate School of Science, Kyoto University, Japan

Synthesis and application of hierarchically structured porous materials is an important topic of interest over the last decade. However, even in simple inorganic compounds, it is still difficult to obtain them with controlled multiscale porosity. In this research, we have successfully prepared crystalline α-Fe2O3 monoliths with well-defined macropores and mesostructured skeletons via sol-gel processes accompanied by phase separation. The size of macropores was controlled by freezing the transient structure of polymerization-induced phase separation. The dried gels (xerogels) were amorphous and possessed high surface area over 400 m2 g-1, whereas a heat treatment at 250-400 ˚C allowed the control of mesoscopic structures with narrow pore size distributions. When the as-dried gels were heated at 350 ˚C, the resultant gels transformed to crystalline α-Fe2O3 and possessed the specific surface area of 120 m2 g-1 without collapse of macrostructures and bulky monolithic forms. Examinations have been carried out using scanning electron microscopy, mercury porosimetry, thermogravimetry-differential theramal analysis, X-ray diffraction, and nitrogen adsorption-desorption.


CI:P05  Preparation of Hierarchically Porous Cerium-based Monoliths from Metal Salt Precursor
SHOTA MAKIMOTO, K. KANAMORI, K. NAKANISHI, Department of Chemistry, Graduate School of Science, Kyoto University, Japan

Monolithic materials with hierarchical macropores and mesopores are advantageous for efficient liquid-phase separations and reactions. We have synthesized hierarchically porous cerium-based monoliths from a metal salt precursor such as CeCl3-7H2O and Ce(NO3)3-6H2O by the sol-gel process accompanied by phase separation. Propylene oxide (PO) was used as a proton scavenger, which promoted polycondensation and solidified the transient structure of phase separation. The macropores can be induced and controlled by varying the amounts of solvent and phase separation inducer such as poly(acrylic acid) (HPAA) and polyethylene oxide (PEO). The color of the wet gels prepared in the presence of PEO was changed from colorless to yellow during solvent exchanges with 2-propanol, which indicates that cerium was oxidized. However, the gels prepared with HPAA did not change the color. After the calcination of the as-dried gels, mesopores about 10 nm were formed as the interstices of crystallites. These gels would be beneficial for applications such as catalysts for liquid-phase reactions.


CI:P06  Synthesis of MgO Porous Monoliths via Sol-gel Process Accompanied by Phase Separation
XUANMING LU, K. KANAMORI, K. NAKANISHI, Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan

Magnesium oxide (MgO) is widely applied as basic catalyst, catalyst support, and CO¬2 adsorbent. Although nanoparticles and aerogels in MgO composition have been known, the difficulty of reuse/recycling and the high cost of production hinder their industrial applications. In contrast to nanoparticles, hierarchically porous monoliths not only supply high specific surface area for active sites, but also possess advantages in materials transport and reusability/recyclability. In this work, we employed magnesium chloride as precursor and PVP as network supporter and phase separation inducer to prepare Mg-based monolithic gels. After solvent exchange, drying and heat treatment at 500 °C, MgO monoliths with the co-continuous macroporous structure with specific surface area of 51-71 m2 g−1 have been obtained. The CO2 capture capacity of the MgO monoliths is dominated by the heat treatment conditions, including heating rate and temperature and atmosphere.


CJ:P01  Magnetic and Dielectric Properties of Thermally Conductive Sheets Effective for Reducing Radiated Emissions from Heat Sinks
TAKASHI TAKEO, N. OHTA, Mie University, Tsu, Mie, Japan; T. MATSUZAKI, Kitagawa Industries Co. Ltd., Kasugai, Aichi, Japan

Heat sinks are often used over electronic components that generate a large amount of heat. In most cases, a thermally conductive sheet generally made of a composite elastomer is placed between the circuitry and the heat sink for efficient heat transfer. Engineers choose the constitutive parameters, that is, the permittivity and permeability of the sheets to meet conditions regarding their heat transfer characteristics and mechanical resilience. This is done by embedding certain kinds of fillers such as ceramic or magnetic powders within the matrix. Heat sinks can also be a source of radiated electromagnetic noise. Recently, it has been pointed out that the radiated emissions are affected by the constitutive parameters of the sheets. In this study, we investigate relationships between the complex permeability or permittivity and the radiated emissions for various materials and structures of the sheets. Our electromagnetic simulation suggests that the real part of the sheet permittivity and the permeability tends to lower the resonance frequencies, while the imaginary part is effective in reducing the level of the radiated emissions over a wide frequency range. Furthermore, the magnetic properties have been found to be more influential than the dielectric ones for our purposes.


CJ:P05  Synthesis of BaTiO3 Nanofibres and their Influence on the Properties of Barium Titanate Composite Fibers
T. SEBASTIAN, A. MICHALEK, T. LUSIOLA, F. CLEMENS, Empa - Swiss Federal Laboratories for Materials Science and Technology, Laboratory for High Performance Ceramics, Dübendorf, Switzerland

Piezoelectric fibers are widely used in composites for actuator and sensor applications due to its ability to convert electrical pulses into mechanical vibrations and transform the returned mechanical vibrations back into electrical signal. They are beneficial for the fabrication of composites especially 1-3 composites, active fiber composites (unidirectional axially aligned piezoelectric fibers sandwiched between interdigitated electrodes and embedded in a polymer matrix) etc., with potential applications in medical imaging, structural health monitoring, energy harvesting, vibration and noise control. Although, fibers made of lead zirconate titanate based systems have been studied widely, lead-free piezoelectric fibers have not been explored often. In this contribution, piezoelectric BaTiO3 fibers were fabricated using thermoplastic extrusion and their electromechanical properties were investigated. Additionally, nanofibers of BaTiO3 have been manufactured using electrospinning and their influence on the extruded BaTiO3 fibers was studied. The nanofibers are incorporated in the BaTiO3 feedstock and extruded as a fiber and sintered. Such fibers show a substantial increase in polarization and strain compared to the BaTiO3 fibers without any nanofibers.


CJ:P07  Electrical Properties of ZrO2 Added Lithium-titanium-zinc Ferrite Ceramics
E. LYSENKO, A. SURZHIKOV, S. NIKOLAEVA, Tomsk Polytechnic University, Tomsk, Russia

As was shown by early studies, zirconium dioxide, ZrO2, can be used in small amounts as an effective additive in ferrite materials manufacturing, which significantly affects the microstructure, electrical and magnetic properties as well as mechanical properties of ferrites. In this work, the influence of ZrO2 addition on the electrical conductivity of Li-Ti-Zn ferrite was studied. The ferrite samples from Fe2O3, Li2CO3, TiO2, ZnO and MnO raw materials were prepared by standard ceramic technology. The oxides were dried, mixed and then calcined to produce the Li0.65Fe1.6Ti0.5Zn0.2Mn0.05O4 ferrite. The calcined powder were milled with various amount of ZrO2 (0.2-3 wt%), compacted in the form of pellets and then sintered in a laboratory furnace. The electrical conductivity of the Li-Ti-Zn ferrite was investigated by two-probe spreading resistance method. It was established that the addition of zirconia affects the microstructure and electrical properties of ferrites. With a small amount of additive up to 0.2 wt%, the activation energy and electrical resistivity are greatly reduced. Further increase in the amount of the additive leads to increase in electrical resistivity so that it exceeds by an order of magnitude compared to pure ferrite.


CJ:P10  Local Electrostatic and Ferroelectric Properties of P(VDF-TrFE)/ Graphene and  P(VDF-TrFE)/ Graphene Oxide Composite Nanofibers 
M.V. SILIBIN¹, V.S. BYSTROV^{1, 2}, D. KARPINSKY^{1, 3}, P. MIRZADEH⁴, P.A.A.P. MARQUES⁴, N. NASANI⁴, G. GONCALVES⁴, B.A SINGH⁴, I.K. BDIKIN^{1, 4}, ¹National Research University of Electronic Technology, Shokina Square, Building 1, Zelenograd, Moscow, Russia; ²Inst. Mathematical Problems of Biology, Keldysh Institute of Applied Mathematics RAS, Pushchino, Moscow region, Russia; ³Scientific-Practical Materials Research Centre of NAS of Belarus, Minsk, Belarus; ⁴TEMA-NRD, Mechanical Engineering Department and Aveiro Institute of Nanotechnology (AIN), University of Aveiro, Aveiro, Portugal

Future developments in nanoscale electronics require tools for local manipulation and probing of stored charge. Charge storage and manipulation at the nanoscale is particularly important to nonvolatile floating gate memory devices such as 2D nanocrystal / piezoelectric composite based memories. Such devices potentially offer both superior nonvolatile memory performance relative to conventional flash memories, and a simple design that is scalable to nanometer dimensions. Graphene (G), with its simple technology, is the material of choice for these devices as composite structures can be fabricated cheaply and reliably. In general, however, nanoparticle synthesis methods introduce defects in the graphene host which can affect charge injection and charge retention. Copolymers of poly (vinylidene fluoride) and poly trifluoroethylene wiz. P(VDF-TrFE) is a promising material for these composite microstructures. In the past several years, nanocomposites consisting of PVDF and graphene or graphene oxides (GOs) are of much interest. Additionally, nano-carbon materials process better interfacial bonding with the polymer matrix. This paper describes composite fibers (multiscale modelling and measurements of physical properties) of copolymer P(VDF-TrFE) with varying concentration of G and GO.


CJ:P11  Development and Application of Hybrid Materials Obtained by In situ and Ex situ Synthesis
C. VENEGAS^{1, 2}, S. BOLLO¹, D. RUIZ², ¹Universidad de Chile, Santiago, Chile; ²Universidad de Santiago de Chile, Santiago, Chile

Today, interesting advances in materials science research, especially in the field of nanomaterials have led to the rapid development of different kinds of sensors for a wide range of analyte detection with improved detection characteristics. We have obtained nanostructured hybrid materials of cobalt oxides with inverse spinel structures and a carbon-based material Co2TiO4 and Co2SnO4 with reduced graphene oxide (CTO/OGR and CSO/OGR, respectively). Two routes of synthesis were adopted, in situ and ex situ to synthesize these hybrids. We have structurally characterized these hybrid materials and are studying a new electrochemical application of these materials in the detection of analytes of biological interest. SEM characterization showed that the morphology and size of CSO and CTO are similar in both synthesis, alone and in the presence of graphene, with an average particle size of 100 nm. TGA characterization confirmed the proportion of CSO/OGR and CTO/OGR. Currently, we are studying the different variables that produce changes in the electrochemical response between the in situ and ex situ hybrid.


CJ:P13  Electrical Characterization of SrTiO3 Solid Solution with Pr3+ and Zr4+
G. LOPEZ-PACHECO, A. REYES-MONTERO, M.E. VILLAFUERTE-CASTREJÓN, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Ciudad de México, México; F. GONZÁLEZ-GARCÍA, Departamento de Ingeniería de Procesos e Hidráulica, Universidad Autónoma Metropolitana, Ciudad de México, México

Lead-free perovskite, with high dielectric constant and switchable electric polarization, are becoming very attractive for use in several devices as memory storage. The SrTiO3 (STO) has a simple perovskite structure that is cubic down to 110 K. The doping effect in ceramic oxides using rare earth cations causes structural and chemical alterations modifing their optical, magnetic and electrical response. Moreover, a low concentration of isovalent dopant on B site, produce lattice instability which can result in high sensitivity to external fields and could even induce ferroelectricity. In this work, STO solid solution with Pr3+ and Zr4+ substituting the A and B site, respectively, Sr1-1.5xPrxTi1-yZryO3 (SPTZO), was successfully synthetized by Pechini route at lower temperature and reduced calcination times X-ray diffraction, Scattering Electronic Microscopy and density measurements were used to characterize the solid solutions synthetized. Crystallographic parameters were calculated by Rietveld refinement. Electrical response of the SPTZO ceramics was performed in high dense pellets (≥ 95%). Dielectric permittivity and loss tangent, as a function of temperature, as well as ferroelectric loops are presented and discussed in the present work.


CJ:P17  Structural, Dielectric and Optical Analysis of Li2O–Nb2O5–TiO2 Based Dielectric Ceramics
S. BAHEL, R. SINGH, Dept. of Electronics Technology, GND University, Amritsar, India

Microwave dielectric ceramics have been used extensively for wireless communications, ultra-high-speed LANs, intelligent transport systems, satellite communications etc. High relative permittivity, low loss, near zero temperature coefficient of resonant frequency (τf) and moderate to low sintering temperature are the key requirements of these materials. In present work, M-phase Li1.14Nb0.86Ti0.14O3, Li1.055Nb0.765Ti0.28O3 and Li1.01Nb0.63Ti0.46O3 solid solutions were synthesized in the Li2O–Nb2O5–TiO2 system by solid state reaction method sintered at 1100 C and subsequently characterized for structural and dielectric properties. XRD spectra indicated hexagonal structure with the formation of superstructure for higher Ti content (≥28 mol%). Closely packed plate-like shape grains with low porosity were observed in SEM images and also confirmed by high relative density (>92 %). From TEM analysis, particle size was found to be in the range 386 – 279 nm. The dielectric properties namely, relative permittivity varied from 51.6 to 36.6; loss tangent from 0.02 to 0.13 and τf from -97 to 6 ppm/ C with increase in Ti contents from 14 mol% to 46 mol% at 1 MHz frequency. These materials are suitable candidate for resonator, filter and antenna components to be used in future wireless systems.


CK:P03  Crystal and Magnetic Structure of Bi1-xLaxFe1-yMnyO3 Ceramics
D.V. KARPINSKY^{1, 2}, S.V. DUBKOV¹, I.O. TROYANCHUK^{1, 2}, M.V. SILIBIN¹, V.A. KHOMCHENKO³, ¹National Research University of Electronic Technology “MIET”, Zelenograd, Moscow, Russia; ²Scientific-Practical Materials Research Centre of NAS of Belarus, Minsk, Belarus; ³CFisUC, Department of Physics, University of Coimbra, Coimbra, Portugal

BiFeO3-based perovskite-like materials have attracted a great attention of the researchers in the field of condensed matter physics. Recent investigations testify that BiFeO3-based compounds with a substitution of Bi- and Fe ions can simultaneously possess polar structure and a weak ferromagnetism. In the current abstract we report on the crystal structure and magnetic properties of Bi1-xLaxFe1-yMnyO3 compounds as a function of the dopant ions and temperature. The X-ray and neutron diffraction data obtained for the Bi1-xLaxFe1-yMnyO3 ceramics have confirmed single-phase rhombohedral crystal structure for the compounds with x ≤ 0.16 and y ≤ 0.1. Chemical substitution with La ions fosters a formation of the PbZrO3-like anti-polar orthorhombic phase, in contrast, doping with Mn ions leads to a transformation into the non-polar orthorhombic structure accompanied with significant reduction in the unit cell volume. Temperature increase causes structural transformation into the non-polar orthorhombic phase regardless the crystal structure of the compounds stable at room temperature. Chemical doping in B-perovskite position with Mn ions slightly decreases the Neel temperature while stabilizes weak ferromagnetic structure with remnant magnetization of about 0.1 emu/g.


CL:P02  Crystal Structure, Electronic Structure, and Photoluminescence Properties of Eu3+ Doped (Li,Na,K)LaMgWO6 Red Phosphors 
WEIGUANG RAN¹, JUNG HYUN JEONG¹, KIWAN JANG², HO SUEB LEE², ¹Department of Physics, Pukyong National University, Busan, South Korea; ²Department of Physics, Changwon National University, Changwon, South Korea 

In this paper, a series of (Li,Na,K)LaMgWO6:Eu3+ phosphors were synthesized by solid state reaction method. The structural properties including the phase purity and structural parameters were analyzed through Rietveld analysis. Meanwhile, the energy band structure of KLaMgWO6 was measured with an ultraviolet-visible diffuse reflection spectroscopy (UV-vis DRS). The electronic structures were calculated using the plane-wave density functional theory (DFT). The evolution of the crystal structures and the relationship with the position of excitation bands was studied in detail. The charge transfer band (CTB) of (Li,Na,K)LaMgWO6:Eu3+ phosphors is situated at ultraviolet and near-ultraviolet region from 250-410 nm. The phosphors show intense absorption bands in near ultraviolet-blue region and exhibit intense pure red emissions under 300-340 nm and 394 nm excitation. Excellent luminescent properties and good color saturation make it be potentially useful in the fabrication of white light-emitting diodes (LEDs).


CL:P03  Direct-write Photolithography for Rapid Prototyping of Silicon Nitride Waveguides on Silicon
D.B. BONNEVILLE, H.C. FRANKIS, J.D.B. BRADLEY, Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada

Silicon-based photonics offers a platform for mass producible photonic components using low-cost manufacturing techniques. These devices rely on patterned waveguide structures which can be defined using a number of different methods. These methods include masked processes such as immersion lithography, or un-masked processes such as electron-beam lithography [1]. Avoiding the need for a physical photomask is an attractive feature for the research environment, where fast turnaround and rapid prototyping of devices is advantageous. Optical direct-write lithography has been demonstrated as a low-cost alternative to e-beam lithography, by patterning waveguides in spin-on polymers [2]. Here, we report on optical direct write lithography as a processing technique for prototyping photonic devices in silicon nitride. Silicon nitride is high-refractive-index contrast and low-loss waveguide platform [3], where e-beam resolution is not always necessary and is therefore required minimum feature sizes are achievable by optical direct writing. Using a 250-nm-thick negative photoresist layer, we define an etch mask with submicrometer resolution using 405nm laser light on an optical direct writing stage. After etching and removal of the resist, high-index contrast strip waveguides are defined. We report on the structural and transmission characteristics of straight waveguides and demonstrate passive integrated optical components including optical couplers and Sagnac interferometers. This process shows promise in being applied to a variety of glass waveguide materials compatible with silicon.


CL:P05  Cation Exchange Mediated Synthesis of Ternary Alloyed Plasmonic Cu3BiS3-xSex Nanorods
S. PAUL, S.K. DE, Department of Materials Science, Indian Association for the Cultivation of Science, Kolkata, India

We report a robust methodology for synthesizing monodisperse Bi2S3‑xSex nanorods (NRs) and characterize their structural and optical properties. The intercalation of Cu(I) into the Bi2S3‑xSex NRs converted them to ternary Cu3BiS3-xSex NRs. This transformation was achieved by adding Cu(I) under specific reaction conditions to the presynthesized Bi2S3‑xSex rods, and the transformation was monitored through the formation of core/shell Bi2S3‑xSex /Cu3BiS3-x Sex nanorod heterostructures. Near -infrared (NIR) bi modal localised surface plasmon resonance (LSPR) was observed upon introduction of Cu(I) ion into the Bi2S3‑xSex matrix. The bi modal plasmon was red-shifted with increasing Se content in the ternary alloyed samples. The LSPR sensitivity, defined as the change in the LSPR peak wavelength per unit change in the refractive index (RI) of the medium, was estimated to be 243 nm/RIU, which was comparable with the other copper chalcogenides like Cu2S/Cu2Se. We suppose that the origin of LSPR might be due to the Cu vacancies as reported for plasmonic copper chalco¬genides. The resulting Cu3BiS3-xSex nanocrystals will provide new opportunities in solution-processed optoelectronic devices.


CM:P01  Densification Behavior of Clay Brick Body Incorporated with Coffee Grounds Waste 
K.A. VASCONCELLOS, P.F. BUSCH, J.N.F. HOLANDA, Group of Ceramic Materials/LAMAV, Northern Fluminense State University - UENF, Campos dos Goytacazes, RJ, Brazil

In many places of the world large amounts of coffee grounds waste from the services sector are discarded. The final disposal of this solid waste material is usually quite problematic for the service sector. This work investigates the effect of coffee grounds waste on the densification behavior of clay brick body. Five clay brick compositions containing up to 10 wt.% of coffee grounds waste as a replacement of natural clay were prepared. Clay brick bodies were pressed, dried and then fired at 950 ºC. The densification behavior was evaluated by four parameters: linear shrinkage, water absorption, apparent density, and mechanical strength. The fired microstructure was evaluated by SEM and XRD. The experimental results showed that the densification behavior of clay brick body was influenced by the coffee grounds waste. In particular, the coffee grounds waste act as pore formation agent in clay bricks. The more the coffee grounds waste amount added to the clay brick body the more intense is this effect on the densification and fired microstructure. Despite this, coffee grounds waste could be used in clay brick bodies as partial replacement for natural clay, resulting in economical and environmental advantages.


CM:P02  Study of Industrial WastesTreated by Hydrocyclones for Use in Ceramic Mass Formulations 
A. ARAUJO, L. CAMPOS, D. MACEDO, R. DUTRA, Federal University of Paraíba, João Pessoa, Paraíba, Brazil

Hydrocyclones are important equipments for the separation of solids-liquid or liquid-liquid suspensions. Industrial waste is currently an environmental concern when not disposed of properly. The treatment of industrial waste by hydrocyclones can separate unwanted fractions from waste and provide new uses for waste as raw materials for the manufacture of traditional ceramic products. In this work three different industrial wastes, kaolin wastes, porcelain polish wastes and granite wastes were hydrocycloned and characterized. Samples no subjected to the hydrocycloning process were used as reference materials. The samples were characterized by X-ray diffraction, X-ray fluorescence, particle size analysis and thermogravimetric analysis. The technological properties were determined in samples prepared and fired at 900 – 1200 °C. The technological properties of fired samples were affected by the particles characteristics, as expected. Some samples exhibited increased linear retraction, apparent density and flexural strength, and decreased water absorption and apparent porosity. Therefore, the improved properties of wastes processed by hydrocycloning allow to open the window of their industrial applications, including tile ceramics.


CM:P03  Pigmented Glazed Ceramic Roof Tiles: Optical Behavior Using the Kubelka-Munk Model in Solar Spectrum Range
L.M. SCHABBACH, M. FREDEL, CERMAT - UFSC, Florianopolis, Santa Catarina, Brazil; D.L. MARINOSKI, S. GÜTHS, CB3E - UFSC, Brazil; A.M. BERNARDIN, UNESC, Brazil

In the ceramic industry the Kubelka-Munk model (K-M) is generally used to describe the optical behavior of the pigments in the visible region, but it can also be used throughout the UV-Vis-NIR spectrum to evaluate the properties of solar reflectance. In this work firstly the solar reflectance and the thermal emittance were determined for the “Portuguese” and “American” colored glazed roof tiles in order to obtained the solar reflectance index (SRI). Nineteen glazed roof tiles (from four different producers) with different colors were studied according to the solar properties and LEED certification. The optical behavior of the colored glazes for the range of the solar spectrum (300 - 2500 nm) was determined using the Kubelka-Munk model through the relationship between the absorption (K) and scattering (S) coefficients. The results show that most of the colored glazed tiles did not meet the 2013 LEED requirements, that demands a SRI ≥ 39, for high slope roof tiles.The K-M analysis for some glazes showed that there was a high absorption of radiation in the near infrared region for them, suggesting that the pigments used for those glazes do not exhibit cool properties. Therefore, cool pigments with higher reflectance should be used to improve the performance of those glazes with low SRI.


CN:P01  High-temperature Ceramic Sensors for Assessing Refractory and Component Conditions 
K. SABOLSKY, G.A. YAKABOYLU, K.A. SIERROS, E.M. SABOLSKY, M.R. COMPARETTO, D.S. REYNOLDS, West Virginia University, Morgantown, WV, USA; J. BOGAN, M. RAUGHLEY, J. SAYRE, Harbison Walker International Technology Center, West Mifflin, PA, USA

The applications for high-temperature, wireless sensor system are numerous for the energy and manufacturing industries, especially for monitoring the health and process conditions of refractory brick and active components within extreme conditions. There are very few refractory materials that are capable of withstanding extreme and variable conditions, which include high temperature, high pressure, various pO2 levels and corrosive conditions (molten inorganics or reactive gasses). In this work, the high-temperature stability and electrical properties of conductive ceramics based on silicide/oxide and semiconducting oxides were investigated. These composites were patterned onto ceramic substrates and embedded within refractory brick to form embedded thermistors, thermocouples and spallation sensor architectures. In addition, sensor designs that include capacitive and inductor elements for RF passive wireless communication were also evaluated. The presentation will describe sensor design, fabrication processes, and testing protocols up to 1400 ºC to assess sensor performance. After testing, the composition and microstructure of the sensors were characterized by XRD, XPS and SEM.

 
CA:HP19  Effect of Tb3+ doping and Self-generated Pressure on the Crystallographic/Morphological Features and Thermal Stability of LaPO4∙nH2O Single-Crystal Nanorods Obtained by Microwave-Assisted Hydrothermal Synthesis
M.T. COLOMER¹, A.L. ORTIZ², ¹Instituto de Cerámica y Vidrio, CSIC, Madrid, Spain; ²Depto de Ingeniería Mecánica, Energética y de los Materiales, Universidad de Extremadura, Badajoz, Spain

The effect of Tb³⁺-doping content (in the range 0‒20 mol.%) and autogeneous/self-generated pressure (in the range 2.3‒3.4±0.1 bar) on the crystallographic/morphological features and thermal stability of single-crystal nanorods of LaPO₄∙nH₂O obtained by a simple and fast microwave-assisted hydrothermal synthesis was investigated. It is shown that high-quality (that is, well-shaped and linear/planar defect free) rhabdophane-type single-crystal La_1-xTb_xPO₄∙nH₂O (x=0‒0.20) nanorods, with a high morphological uniformity, are obtained in all cases. In addition, it is shown that the Tb³⁺ solutes are incorporated into the LaPO₄∙nH₂O host, forming substitutional solid solutions (i.e., partial substitution of La³⁺ by Tb³⁺) with progressively smaller unit-cell volume but with identical thermal stability. Morphologically Tb³⁺ doping however results in the formation of nanorods with lower aspect ratio, and in particular in nanorods that are much shorter but essentially equally thick. With respect to the self-generated pressure during the microwave synthesis, it is shown that its increase does not affect to crystallographic aspects, but however results again in nanorods with lower aspect ratio. It is also demonstrated that monazite-type single-crystal La_1-xTb_xPO₄ nanorods can be obtained by calcining their rhabdophane-type La_1-xTb_xPO₄∙nH₂O counterparts at ~700 ºC in air, with a higher Tb³⁺-doping content and self-generated pressure leading as well to lower aspect-ratio calcined nanorods.


CA:HP20  Translucent High Strength Glass-ceramic Nanocomposite for Dental Restoration
LE FU, H. ENGVIST, WEI XIA, Div. Applied Materials Science, Dept. of Engineering Sciences, Uppsala University, Fagersta, Sweden

ZrO2-based full ceramic has been widely accepted as a promising dental ceramic because of their excellent mechanical properties and good biocompatibility. However, the increase of the transparency will result in a significant decrease of their mechanical strength. Glass ceramic (GC) is also one of the most widely used dental restorative materials due to its excellent translucency and good mechanical strength. However, GC generally has lower (normally half of) flexural strength and fracture toughness than the full ceramics, which limits their applications, i.e. for long bridges. It will be interesting if we could improve the flexural strength and fracture toughness of transparent GC close to the full ceramics, i.e. yttrium stabilized zirconia. A lot of effort has been done, but the improvement is not satisfied. Nanocrystalline materials show significantly improved properties. Among the different types of nanocrystalline materials, tough and high-modulus nanocrystalline glass-ceramics has potential applications in load-bearing parts as a biomaterial. In this study, we developed a translucent high strength ZrO2-SiO2 glass-ceramic nanocomposite by controlling the raw materials and sintering process. It has the high potential for the dental restoration.


CA:HP21  Effect of Plasma Treatment of Polymeric Tape Carriers on Wetting Behaviour of Aqueous Ceramic Tape Casting Slurry
M. TRUNEC¹, P. STASTNY¹, J. KELNAR², M. PAZDERKA², ¹CEITEC BUT, Brno University of Technology, Brno, Czech Republic; ²CEPLANT, Dept. of Physical Electronics, Masaryk University, Brno, Czech Rep.

Due to environmental and health aspects the traditional tape casting slurries based on organic solvents are nowadays being replaced with aqueous systems. An important obstacle associated with the high surface energy of water is the poor wetting of polymeric tape carriers. A low wetting angle of the ceramic slurry cast on the polymeric tape carrier is necessary to obtain thin, homogeneous, and defect-free green tapes of a constant thickness. In our research, we measured the contact angles of an aqueous epoxy-based ceramic slurry on polyethylene terephtalate (PET), polypropylene (PP), polymethyl methacrylate (PMMA), and aluminium-coated polyethylene terephtalate (PET-Al) films, and investigated approaches to improving their wetting. We evaluated the effect of the plasma treatment of tape carrier surface on wetting behaviour and compared it with the effect of the addition of non-ionic amphiphilic surfactants to the ceramic slurry. The treatment of tape carrier surface by low-temperature plasma substantially improved the wetting behaviour of aqueous ceramic slurry. The lowest contact angle of 31° was obtained on the PET film and in this case the addition of a surfactant could be fully eliminated and the potential drawbacks related to the use of surfactants could be prevented.


CA:HP22  Production and Properties of a-TCP containing Bioactive Glass-ceramics
A. DOBRADI, M. ENISZ-BODOGH, K. KOVACS, Institute of Materials Engineering, University of Pannonia, Veszprem, Hungary

Meat processing facilities produce significant amount of raw animal bone waste representing a serious biohazard. For this reason the safe deposition of these bones is of utmost importance. The main mineral constituent of these bones is Ca-phosphate, therefore they can be used as a precursor for production of bioactive glass-ceramics. A process was developed to convert animal bones into a valuable secondary raw material of Ca-phosphate based GC for bone replacement and tissue repair. Bioactive GC containing β-TCP/α-TCP and wollastonite were manufactured from chemically and heat treated, protein-free bovine bone as well as a base glass prepared by melt quenching. Body fluids enhance apatite formation on the surface of Ca-phosphate based bioceramic implants, which in turn improve the bone-binding strength of such devices. A systematic investigation of HAP formation on the surface of bioactive GC immersed into SBF was therefore conducted on GC samples produced from high temperature sintered animal bones. Samples were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffractometry, Vickers microhardness, bending strength and porosity. Dissolved constituent (Ca) of bioactive GC were quantified by XRF analysis of SBF.


CB:HP22  SHS of Advanced Borosilicide High-temperature Ceramics
Yu.S. POGOZHEV, A.YU POTANIN, S. VOROTILO, V.V. KURBATKINA, E.A. LEVASHOV, National University of Science and Technology “MISIS”, Moscow, Russia

Present study devoted to development of refractory borosilicide SHS ceramics in Mo-Hf-Si-B system via two different techniques: forced SHS pressing and hybrid off-line technology SHS + HP (hot pressing). The kinetics of the combustion process was studied. The mechanism of chemical transformations and structure formation of the final synthesis products is proposed. The formation of HfB2 grains starts in the preheating zone at the temperature below the melting point of Si by the mechanism of solid-phase interaction involving gas transport reaction with the participation of B2O2. Then Si melts in the combustion zone and the resulting melt spreads over the surface of other solid reagents. Due to the reaction diffusion, a film of MoSi2 is formed on the surface of Mo particles. At the same time Si melt is saturated with Mo, Hf and B due to their dissolution. The formation of MoB and HfB2 secondary grains occurs in the post combustion zone by crystallization from a supersaturated Si melt. Final product includes MoSi2, HfB2 and MoB phases. Consolidated ceramics demonstrate excellent oxidation resistance at the range of 1200-1600 C. The work was financially supported by the Ministry of Education and Science of the Russian Federation in the framework of state assignment No 11.1207.2017/ПЧ.


CB:HP23  Toward Better Conversion in Magnesiothermic Synthesis of Zirconium Diborides
S. CORDOVA, E. SHAFIROVICH, The University of Texas at El Paso, El Paso, TX, USA

Zirconium diboride (ZrB2) is a promising ultra-high-temperature ceramic material. Self-propagating high-temperature synthesis (SHS) of ZrB2 from elements is well known, but it is not suitable for large-scale fabrication because of high costs of raw materials. Magnesiothermic SHS of ZrB2 is more economically viable as it involves reduction of relatively inexpensive oxides of zirconium and boron. Since the reacting mixtures are low-exothermic, a promising approach is mechanically activated self-propagating high-temperature synthesis (MASHS). However, a significant problem in the MASHS of ZrB2 is low conversion due to loss of magnesium as a vapor during the combustion process. This problem could be overcome by lowering the combustion temperature with a diluent and by adding excess magnesium. In the present work, the effects of MgO, NaCl, and excess Mg on the milling and combustion steps in the MASHS of ZrB2 were investigated. While the addition of MgO was ineffective, excess Mg increased the conversion degree and NaCl improved milling and led to the formation of nanoscale polycrystalline ZrB2 in the SHS process.


CB:HP24  3D Engineered Photoanodes for Dye-sensitized Solar Cells
A. SANGIORGI^1,2, A. SANSON¹, ¹ISTEC-CNR, Faenza, Italy; ²Dept. of Chemistry, University of Parma, Parco Area delle Scienze, Parma , Italy

An important contribution to the improvement of the current energy and environmental issues can derive exploiting the sun for energy production through photovoltaic devices. Among all the different options, in the recent past lot of scientific community efforts have been focused on a rapidly evolving technology, the Dye-sensitized Solar Cells (DSCs). Their key features are high versatility, low cost and the use of environmental-friendly materials. A fundamental DSCs component is the photoanode (typically composed of a mesoporous TiO2 screen-printed film), which represents the device nucleus. The afore-mentioned random porous TiO2 structure is perfectible in order to overcome some undesired characteristics like low conductivity and limited access, for dye and electrolyte, to the entire film surface. Consequently techniques for fabricating photoanodes, with improved both conductivity and accessibility to the semiconductor, are of great interest. In this work, 3D engineered photoanodes, composed by micro-pillars supported onto a mesoporous layer, were produced using a combination of wet-powder spraying (WPS) and the additive manufacturing technique called micro-extrusion. These processes were performed using a fully-automated multi-head machine highlighting their easier scalability.


CB:HP25  Synthesis of Kaolinite-methanol and Kaolinite-cetyltrimethyl-ammonium Chloride Complexes using Solvothermal Methods
A. KOVACS, E. MAKO, Institute of Materials Engineering, University of Pannonia, Veszprem, Hungary

In this study, simple and effective solvothermal methods were used to prepare high-quality kaolinite-cetyltrimethylammonium chloride (kalonite-CTAC) intercalation complex, which is suitable to produce kaolinite nanoscrolls. These halloysite-like nanoscrolls can be applied as nanoscale reactors, carriers, and nanofillers of catalysts, medicines, and nanocomposites etc. Kaolinite-dimethyl-sulfoxide and kaolinite-urea precursors, synthesized by cost-efficient homogenization method, were found to be favourable to produce kaolinite-methanol and kaolinite-CTAC complexes by one-pot and two-pot solvothermal methods. The type of precursor, as well as the reaction time and temperature significantly affect the formation of kaolinite-methanol and kaolinite-CTAC complexes. The influence of these parameters was investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG), and transmission electron microscopy (TEM).


CB:HP26  Multi-phase Armor Production and Characterisation Involving B4C – SiC – TiC with Spark Plasma Sintering Technique
G. UYSAL SAPANCI, G. DARA, D. AKKUŞ KÜRÜM, S. TURAN, F. KARA, A. KARA, Roketsan Inc., Ankara, Turkey

In this study, optimum boron carbide (B4C) - silicon carbide (SiC) - titanium carbide (TiC) multi-phase ceramic composites were designed and produced by spark plasma technique bearing in mind the hardness – toughness – cost – lightness - performance relationship. In addition, the effect of these carbides was also investigated by adding only TiC or SiC powders into pure boron carbide powder. The addition of SiC did not affect the hardness and toughness, but the addition of TiC resulted in increased toughness in spite of decreased hardness. When microstructure analyzes and x-ray diffraction patterns were evaluated together, residual graphite and SiC were found to exist in pure B4C, and when TiC was added, residual graphite and small amounts of SiC, as well as TiC and B4C, reacted to form TiB2. When SiC and TiC were added together, hardness decreased whereas fracture toughness increased. Because of the fact that boron carbide is a light material, all the additives added increase the weight, while the costs were reduced because all the additives are cheaper than B4C.


CD:HP07  Large Area Bonding Technology by using Solid Porous Ag in Die-attached Modules
CHUANTONG CHEN, CHANYANG CHOE, KATSUAKI SUGANUMA, Osaka University, Osaka, Japan

With the fast development of electronic systems, wide band-gap (WBG) semiconductor devices such as SiC and GaN have grown considerably in the applications of large area bonding (>10 x 10 mm2). In this work, a new large area bonding technology was introduced for WBG die-attachment power devices by using solid porous Ag structure which allows low temperature and pressure-less during bonding process. The bonding strength, which was about 25 MPa, did not change much as the chip size was varied from 3 x 3 mm2 to 15 x 15 mm2. This confirms that the technology was not influenced by the chip size, and thus can be used in large area bonding. Transmission electron microscopy (TEM) observation shown a large quantity of single crystal hillocks and Ag nanoparticles (AgNPs) formed at the bonding interface, which bridges the interface in the bonding process. This novel and reliable bonding technology using the solid porous Ag is attractive for the large area bonding required in WBG power device electronic applications.


CD:HP08  Joining and Mechanical Testing of Oxide/Oxide (Nextel TM 610/alumina-zirconia) Ceramic Composite
M.Y. AKRAM¹, M. FERRARIS¹, V. CASALEGNO¹, G. PUCHAS², W. KRENKEL², S. ROSZEITIS³, ¹DISAT, Politecnico di Torino, Torino, Italy; ²Dept. of Ceramic Materials Eng., University of Bayreuth, Bayreuth, Germany; ³Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Dresden, Germany

NextelTM 610/alumina-zirconia continuous oxide fiber composites were successfully joined to themselves by using a novel glass-ceramic based on the system SiO2-CaO-Al2O3-MgO-Y2O3-ZrO2. Dilatometry measurements were carried out to tailor the coefficient of thermal expansion while sintering and crystallization behaviours were investigated by hot stage microscopy and differential thermal analysis, respectively. Joint interfaces were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD) was used to identify the formation of different phases in the glass-ceramic. Single Lap off-set shear tests and four-point bending tests at room temperature and at 850 °C were performed to investigate the mechanical strength of the joints. To check the thermal stability of joined components thermal ageing was performed at 850 °C for 100 h. The results showed that the joined interfaces were well bonded and free from defects and discontinuities. Single Lap off-set shear tests result in delamination of composites. The average flexural strengths of joined samples were 71 MPa and 81 MPa at room temperature and at 850 °C, respectively.


CD:HP09  Brazing Joining of C/SiC to Ti6Al4V and the Joint Strength Improvement by Surface Modification
M.K. BANGASH, V. CASALEGNO, M. FERRARIS, Dept. of Applied Science and Technology, Politecnico di Torino, Torino, Italy

The development of appropriate joining processes to integrate C/SiC composites into an engineering structure and joining with metals is crucial for expanding the structural applications of C-SiC composites and Ti6Al4V alloy. In this study, C/SiC composites were brazed to (i) Ti6Al4V (As-received) and (ii) surface modified Ti6Al4V using Zr-based (Zr-17.3Ti-20Ni-1Hf) brazing alloy. In-house developed Micro-Electro-Discharge Machining (Micro-EDM) was used to modify the Ti64Al4V surface. Around 30% increase in the Ti6Al4V surface area was achieved when V-shaped micro-slots were produced on the Ti6AL4V surface. The microstructure and interfacial reactions were analysed using SEM, EDS and XRD. Single lap offset (SLO) test was adopted to determine the joint shear strength. Results show ~40% higher joint shear strength of C/SiC-Ti6Al4V joints produced with Zr-based joining alloy compared to those produced with conventional Cusil-ABA joining alloys. Further improvement in the joint strength was observed when the surface modified Ti6Al4V surfaces were brazed to C/SiC composites.


CD:HP10  Joining of Monolithic Ceramics (SiC, Alumina, Mullite) by “RM-Wrap”
P.K. GIANCHANDANI, V. CASALEGNO, M. FERRARIS, DISAT-Dept. of Applied Science and Technology, Politecnico di Torino, Torino, Italy

A novel joining technique called “RM-Wrap” method (RM, Refractory metals = Mo, Nb, and Ta) was developed; it consists of wrapping Si foils inside the refractory metal wrap. RM-Wrap was successfully used to join (i) SiC to SiC, (ii) Alumina to Alumina, and (iii) Mullite to SiC. The pressure-less joining process was carried out at 1450 °C for 5 min under a non-reactive environment. The joining material formed is composite made of Si matrix reinforced by disilicides (MoSi2, NbSi2, TaSi2). The joints were thermally aged at 1100 °C in air for 6 hours, in order to characterize their behavior at high temperature in an oxidative environment. The joint morphology (interphase and interface) and elemental composition of the joining material prior and post thermal ageing were investigated in detail using FESEM and EDX which showed uniform, continuous and crack free joints.


CE:HP14  Preparation of Polyvinylpolymethylsiloxane Aerogels with High Bending Strength and Flexibility
M. KURITA, G. ZU, K. KANAMORI, K. NAKANISHI, Dept. of Chemistry, Graduate School of Science, Kyoto University, Japan

Aerogels have attractive properties such as low thermal conductivity, low density, high visible-light transparency and high surface area. Their mechanical strength is, however, too low, and a facile preparation without drying in a supercritical condition had been a big challenge. Organic-inorganic hybridization has been studied in order to improve the mechanical strength and flexibility. We have developed polymethylsilsesquioxane (PMSQ) aerogels by a well-designed two-step sol-gel process using methyltrimethoxysilane as the trifunctional precursor. The PMSQ aerogels show unusually high strength and flexibility and almost complete recovery after 80% uniaxial compression. In order to further increase flexibility against bending, we have recently developed polyvinylpolymethylsiloxane (PVPMS) aerogels, which have a doubly crosslinked structure consisting of hydrocarbon chains and polymethylsiloxane. The precursor vinylmethyldimethoxysilane was first radically polymerized by di-tert-butyl peroxide, and then allowed to gel through hydrolytic polycondensation catalyzed by tetramethylammonium hydroxide. The resultant PVPMS aerogels show improved bending flexibility and low thermal conductivity comparable with the PMSQ aerogels.


CE:HP15  Properties of Mesoporous Silica Aerogel Powders Synthesized by Using a New Gelation Agent
SO-YEON HEO, SANG-EUN LEE, HYE-IN GO, CHANG-KOOK HONG, JIN-SEOK LEE, YOUNG-SOO AHN, Korea Institute of Energy Reaearch, Daejeon, South Korea

This study reports a new synthesis method of silica aerogel powders synthesized by using IPA as gelation material for obtaining hydrogel from silica sol which were prepared by adding HCl to the diluted water glass. Furthermore, the effects of different amounts of HCl on the aerogel properties were examined, while using the same amounts of diluted water glass, IPA as gelation material. The surface modification and solvent exchange simultaneously was carried out with small amount of trimethylchlorosilane, reacting with surface hydroxyl group to give silylated hydrogel and also hexane for displacement of pore water. The total processing time of the aerogel powders production via ambient pressure drying could be reduced to 8hrs. The specific surface areas and pore diameter and pore volume of the aerogel powders were in the range of 345-819 m2/g and 7.87-12.00nm and 0.41-3.14 Cm2/g, respectively. The decomposition temperature of silane group on the surface of silica aerogel powders was investigated by the Differential Scanning Calorimetry(DSC). The experiment results revealed that the aerogel powders with a wide variation in the tap density, specific surface area, pore diameters and volume could be synthesized by varying the inorganic acid adding to the silica sol.


CE:HP16  Atomic Scale Structural Evolution of Co-W Bimetallic Nanoparticles for SWCNTs Catalyst
AKIHITO KUMAMOTO¹, HUA AN², TAIKI INOUE², SHOHEI CHIASHI², YUICHI IKUHARA¹, RONG XIANG², SHIGEO MARUYAMA^2,3, ¹Institute of Engineering Innovation, The University of Tokyo, Tokyo, Japan; ²Dept. of Mechanical Engineering, The University of Tokyo, Tokyo, Japan; ³Energy NanoEngineering Laboratory, AIST, Tsukuba, Japan

Bimetallic nanoparticles promote the selective synthesis of single wall carbon nanotubes (SWCNTs) towards single chirality. Recently, Co-W bimetallic clusters are suggested to selectively produce several types of single-chirality metallic SWCNTs at controlled growth conditions [F. Yang et al., Nature 2014; JACS 2015; ACS Nano 2017]. For detail structural determination, we related that the selectivity is strongly related to an intermediate structure of Co6W6C [An et al., Nanoscale 2016]. 5 min-growth of SWCNT with alcohol catalytic chemical vapor deposition (ACCVD) [S. Maruyama, et al., Chem.Phys.Lett. 2002] will give only Co particles indicating a dynamic evolution of catalyst structure. Here we will report an atom-resolved structural analysis for the early structural evolution of W-Co catalyst within 3 min-growth. The structures of W-Co catalytic nanoparticles are characterized by an aberration-free STEM observation combined with high-sensitive energy-dispersive X-ray spectroscopy (EDS). The evolution of the catalytic nanoparticles is confirmed to W-W6Co6C, W6Co6C, and W6Co6C-Co with pure-Co at as-reduced, 1 min, 3 min-growth, respectively. Regarding coexistence of two-phase in the nanoparticle, we discuss the atomic structure of the heterointerface.


CF:HP06  Carbide Nanocomposite TiC-SiC for Bulk Solar Absorbers Applications
H. ARENA, G. ARRACHART, M. COULIBALY, A. SOUM-GLAUDE, A. JONCHERE, A. MESBAH, N. PRADEILLES, A. MAITRE, X. DESCHANELS, CNRS, ICSM-UMR 5257, Bagnols sur Ceze, France

In concentrating solar power technology, the absorber transfers the energy from the solar radiations to a thermal fluid which will produce electricity. To maximize its efficiency, the absorber should be spectrally selective while maintaining good mechanical, physical and chemical properties under severe operating conditions. Due to its good oxidation resistance, SiC is the material commonly used as the absorber, however, it is not spectrally selective. To improve its optical properties we propose to associate it with TiC, an Ultra-High Temperature Ceramic, in a nanocomposite material. In most studies concerning the optical properties of UHTCs, densified or porous pellets are obtained from commercial powders, and composites are made by mechanical mixing. To improve the homogeneity of the final material, we designed a synthesis route where Si and Ti alkoxide precursors copolymerize, in the presence of sucrose, leading to interpenetrated networks of the two oxides with enclosed carbon source particles. The carbothermal reduction produces a homogenous SiC-TiC nanocomposite with small size crystallites. The powder is then sintered by SPS to produce pellets with various densities. The effects of the TiC-SiC proportion and of the pellet density on the optical properties were studied.


CG:HP06  Non-conventional Synthesis of New MAX Phases
L. BISCHOFF, C.M. HAMM, J.P. SIEBERT, C.S. BIRKEL, Technische Universitaet Darmstadt, Darmstadt, Germany

Since their discovery in the 1960s, more than 70 members of the family of MAX phases have been synthesized and many more have been theoretically predicted. Their chemical composition as well as the resulting electronic structure are the key factors that determine their intrinsic physical properties. Beside their widely investigated mechanical properties, their functional properties have gotten into the focus of intense research efforts. One example is the field of magnetic MAX phases where highly interesting magnetic phenomena have been reported, particularly in the area of thin film MAX phases. However, the synthesis of both, thin film and bulk, MAX phases with later transition metals with high magnetic moment is very challenging. We therefore investigate synthesis techniques that allow the incorporation of “new” elements into the MAX phase structure. One of our strategies involves the non-conventional solid-state methods, microwave heating and spark plasma sintering, that allow for example the synthesis of Mn- (and Fe-) doped Cr2AlC and V2AlC. We use local and bulk characterization techniques to investigate the (micro)structure on different length scales and to fully understand the resulting properties of the obtained materials.


CG:HP07  Synthesis, Structure and Catalytic Properties of a New Member of the MXene Family: V4C3Tx
MINH HAI TRAN, T. SCHAEFER, C.S. BIRKEL, Technische Universitaet Darmstadt, Darmstadt, Germany

Since the discovery of MXenes as a new class of two-dimensional materials, more than 20 different MXene have successfully been synthesized and many more have been predicted theoretically. They are very promising materials for various applications due to their unique physical and chemical properties. Consequentially, they are discussed in the context of a variety of applications, such as battery materials, heterogeneous electrocatalysts, sensors, and many more. Herein, we can add a new “43”-type carbide MXene to the family. The synthesis of V4C3Tx was realized through selective etching of V4AlC3 using hydrofluoric acid. The required precursor MAX phase V4AlC3 was initially synthesized via a non-conventional solid-statemethod, microwave heating. The characterization of both structures were carried out by X ray powder diffraction and electron microscopy techniques. Furthermore, we present the catalytic performance towards the hydrogen evolution reaction of the new V4C3Tx MXene.


CG:HP08  Zr and Nb based MAX Phases as Accident Tolerant Fuel Cladding
D. BOWDEN¹, J. WARD¹, T. UNGAR^1,2, S. SHAH³, S. DE MORAES SHUBEITA¹, T. LAPAUW⁴, J. VLEUGELS⁴, K. LAMBRINOU⁵, E. ZAPATA-SOLVAS⁶, M. PREUSS¹, P. FRANKEL¹; ¹The University of Manchester, UK; ²Eötvös University Budapest, Hungary; ³University of Cambridge, UK; ⁴KU Leuven, Belgium; ⁵SCK•CEN, Belgium; ⁶Imperial College London, UK

MAX phases are nanolayered ternary carbides, which exhibit a combination of metallic and ceramic properties. Zr-based materials offer good neutronics and MX-type Zr carbides are shown to offer superior irradiation damage tolerance. New types of Zr-based MAX phases are being studied within the CAFFE (carbides for future fission environments) consortium, which is assessing the optimal stoichiometry and suitability of these new materials for generation III+ nuclear environments. Proton irradiated Zr-based MAX phase alloys have been produced and subsequently analysed using several x-ray diffraction (XRD) techniques. XRD allows us to measure irradiation-induced microstructural changes, such as the alteration of lattice parameters and atomic positions within these materials. Alongside this, we can utilise line profile analysis techniques to calculate any changes in dislocation density arising from irradiation. These results are compared to modelled data which predicts lattice changes due to differing types of defect accumulation, such as antisite defects and Frenkel pairs.


CG:HP09  Electronic and Vibrational Properties of 3D MAX Phases and 2D MXenes: From Experiments to First-principles Modeling
A. CHAMPAGNE, L. SHI, T. OUISSE, B. HACKENS, F. BOURDAROT, P. BOURGES, P. PIEKARZ, D. PINEK, I. GÉLARD, M.W. BARSOUM, J.-C. CHARLIER, Université Catholique de Louvain, Louvain-la-Neuve, Belgium

MAX phases are layered 3D solids composed of 2D sheets of MX separated by A layers. They exhibit a general formula Mn+1AXn where M represents an early transition metal, A represents a group A element, X is either C or N and n varies from 1 to 3. By now it is well-established that they combine some of the best properties of ceramics and metals. In 2011, the removal of Al layers from the 3D MAX phase by hydrofluoric acid treatment and sonication was demonstrated, resulting in a 2D system called MXene. Today more than 20 separate MXenes have been successfully synthesized and both structure and physical properties of many more have been theoretically predicted. A wide variety of physical properties of crystals can be deduced from their lattice-dynamical behavior. Moreover, inelastic neutron scattering and Raman spectroscopies can be used to identify samples’ composition and quality, once their fingerprint has been established. We study here, using both experimental and first-principles techniques, the electronic and vibrational properties of 3D MAX phases (Cr2AlC), and 2D MXenes (V2CTx).


CG:HP10  Tracking Phase Changes by In-situ Resistivity Measurements of Amorphous Cr2AlC Thin Films at High Temperatures 
B. STELZER, X. CHEN, P. BLIEM, J.M. SCHNEIDER, Materials Chemistry, RWTH Aachen University, Aachen, Germany

Magnetron sputtered, amorphous Cr2AlC thin films were annealed at a constant heating rate in vacuum up to 800 °C. Throughout the annealing process the electrical resistivities of the samples were measured. At temperatures above 552 °C and 585 °C reductions of the resistivity by 4 and 20%, respectively were observed. These changes correlate with measured phase transitions from amorphous to disordered solid solution and further to MAX phase and are in good agreement with differential scanning calorimetry measurements. The results demonstrate in-situ tracking of phase changes by non-destructive resistivity measurements.


CG:HP11  Low Temperature Synthesis of Crystalline MoAlB Coatings by Combinatorial Direct Current Magnetron Sputtering 
J. ACHENBACH, M. HANS, D.J. MILJANOVIC, J.M. SCHNEIDER, Materials Chemistry, RWTH Aachen University, Aachen, Germany; D. PRIMETZHOFER, Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden

Bulk MoAlB was recently reported to hold great promise as a high temperature material as it forms a dense, adherent alumina scale. Here we report the formation of X-ray phase pure, orthorhombic MoAlB coatings (space group Cmcm) at 700°C by combinatorial direct current magnetron sputtering onto Al2O3 substrates. The synthesis temperature compared to bulk processing was lowered by 42%, enabling depositions onto technical relevant substrates such as cemented carbide. Experimentally and theoretically determined lattice parameter and elastic moduli data deviate by <0.4 % and <3 %, respectively, indicating very good agreement.


CH:HP14  Oxidation Resistance Characteristics of SiC-coated Carbon Composites using Polycarbosilane 
SU-BIN AHN, JUNG-WON BANG, YOONJOO LEE, YOUNGHEE KIM, WOOTECK KWON, Korea Institute of Ceramic Engineering and Technology, Jinju-Si, South Korea

Carbon composites show superior high temperature performance. A major drawback is oxidative property at high temperature in an atmospheric condition, which strictly limits its applications. In this study, to improve oxidation resistance properties, SiC(Silicon Carbide) coating was applied on a carbon composite using a polycarbosilane. The microstructure of the SiC coated carbon composite was observed with FESEM, and oxidation resistance properties were measured by mass loss method in an air atmosphere of 400 °C and 700 °C. The oxidation resistance properties of SiC coated carbon composites gave much improved oxidation resistance than uncoated carbon composites. However, there is no change in thermal conductivity after coating using a polycarbosilane.


CH:HP15  Nanoparticles Deposition by Plasma Gas Condensation Process  
I. CARVALHO^1,2, S. CALDERON V.⁴, P. J. FERREIRA^4,5, A. CAVALEIRO^1,2, S. CARVALHO^1,3, ¹SEG-CEMMPRE Mechanical Engineering Dept., University of Coimbra, Coimbra, PT; ²IPN-LED&MAT Instituto Pedro Nunes, Lab. for Wear, Testing & Materials, Coimbra, PT; ³UCFUniversity of Minho, Dept. of Physics, Campus of Azurém, Guimarães, PT; ⁴INL - International Iberian Nanotechnology Lab., Braga, Portugal; ⁵Materials Science and Engineering Program, The University of Texas at Austin, Austin, Texas, USA

In the last decade, nanoparticles (NPs) have attracted a lot of attention because of their unusual characteristics when compared to bulk material, such as reactivity, antibacterial, optical and magnetic properties among others. In this study, ZnFe bimetallic NPs and AgAu bimetallic NPs were produced by plasma gas condensation process onto carbon substrates to exploit the galvanic couple formed for such dissimilar metals. ZnFe NPs are expected to provide oxygen scavenging promoted by galvanic corrosion properties for food packaging applications; while AgAu NPs are expected to form a galvanic pair pro-moting the Ag+ release to incorporate in carbon matrix for biomaterials applications, namely ureteral stents with the purpose of reducing microbial encrustation.


CJ:HP18  Fabricating Polymer-ceramic Composite Films via EPD  
M. FREY¹, E. CRUZ¹, M. MAUCK¹, T. HANEMANN^1,2, ¹University of Freiburg, Dept. of Microsystems Engineering - Lab. for Materials Processing, Freiburg, Germany; ²Karlsruhe Institute of Technology, Institute of Applied Materials, Karlsruhe, Germany

A process to produce ceramic-polymer functional composite films via electrophoretic deposition is presented in this work. As the ceramic main component, Barium titanate was chosen due to its good commercial availability and its high dielectric properties. To improve the stability of the ceramic green films PMMA was added as a polymer binding component. The electrophoretic deposition was carried out in a suspension containing ceramics, polymer, a dispersion agent and a mixture of isopropanol and acetone as the dispersion medium. The so prepared sampled were characterized by their mass, their thickness, their polymer content and their dielectric properties. The effects of suspension composition, the deposition time and the particle size distribution were studied. The composites exhibited a polymer content between 0 to 6 % and a relative permittivity up to 80 at 100 kHz. This opens new possible process paths in the manufacturing of thin ceramic filled capacitors or lightweight small passive antennas.


CM:HP05  Processing and Characterization of Composites with an Acid Based-geopolymer Matrix  
V. MATHIVET¹, J. JOUIN¹, H. CELERIER¹, N. TESSIER-DOYEN¹, S. ROSSIGNOL¹, M. PARLIER², ¹IRCER, Centre Européen de la Céramique, Limoges cedex, France; ²ONERA, Châtillon, France

The alkali-based geopolymers are only studied for a few decades. However, their alkaline properties can be detrimental when used in composites with certain types of fibers. For this application, a new type of geopolymer, based on the reaction of the metakaolin with phosphoric acid and developed lately revealed good mechanical properties as well as chemical stability, in particular under fire. In this work, metakaolins with different reactivities were used to study the influence of the Al/P ratio on the consolidation time and properties of these new geopolymers. These materials, consolidated at temperatures ranging from 20 to 70°C, were used as matrices in the processing of composites with fibers. The samples, both raw matrix and composites, were characterized in order to better understand their chemistry, microstructure and mechanical stability. The phase composition and structure were studied using X-ray diffraction and time-resolved Fourier Transform Infrared. Scanning electron microscopy and Energy Dispersive Spectroscopy showed the microstructure and phases distribution in the matrix and composite. Mechanical characterizations confirmed the good behavior of acid based- geopolymers. Finally, for all the samples, the water and fire resistances were evaluated.


CM:HP06  Lightweight Ceramic Tiles for the Production of Ventilated Façades: Control and Prediction of the Porosity-property Relations  
C. MOLINARI, C. ZANELLI, G. GUARINI, M. DONDI, CNR-ISTEC Istituto di Scienze e Tecnologia dei Materiali Ceramici, Faenza, Italy

In the building sector, it is ever more important the development of new solutions to improve energy efficiency and savings, particularly due to the demanding EU directive. The implementation of ventilated façades, on new and existing buildings, offers the possibility to reduce costs and promote the acoustic and thermal insulation. The thermal performance of the external layer influences the building performances; from this perspective, the porosity plays a key role in the definition of thermal conductibility of the material. For this purpose, it is necessary to design and control the performances of the lightweight ceramic tiles used for the construction of the ventilated façades. In this study, the effect of the addition of SiC like foaming agent for the production of lightweight ceramic materials was studied. Moreover, waste glasses were used in the ceramic formulation, in order to evaluate the recyclability of this materials into the lightweight tiles process technologies. The target is to define the correlation between chemical composition of the mixtures and porosity obtained, in order to tailor it in terms of size and amount of the pores formed. In particular, the link between bulk composition and physical and technological properties of the final products was studied.


CM:HP07  LWAs from Local Clay and Agro-food or Post Consumption Residues for Green Roof or Agronomic Application   
F. ANDREOLA, L. BARBIERI, R.D. FARÍAS, I. LANCELOTTI, Università degli Studi di Modena e Reggio Emilia, Modena, Italy

This research is focused on the evaluation of pores forming action of agro-food (brewery sludge, animal flour ash, corn cob) and post-consumption (spent grounds coffee) residues into lightweight aggregates (LWAS) based on an Italian red clay. These materials were characterized by chemical (XRF), CNSH, mineralogical (XRD) and thermal (TGA/DTA/DSC) analyses. Besides, other LWAs mixes were prepared incorporating into the best formulations a fertilizer glass (10-50 wt%) obtained from cullet glass, and animal flour ash and potassium carbonate (P and K intake, respectively) with the aim to use these materials as controlled fertilizers. All the LWAs mixes were shaped to formed approximately spherical pellets and thermal treated at 1000 °C for 1 hour. Technological parameters were performed in order to test the drainage effect of the products for green roofs (water absorption, density, porosity) or as fertilizer for agronomic use (pH, electrical conductivity, release tests). The results indicate the potential for manufacturing high quality LWAS suitable in green roof, using brewery sludge or coffee residues at 15 wt%. Regarding mixes with glass, good results of pH, conductivity and release of nutrients were found, confirming a positive effect on the soil.


CM:HP08  Green Thinking in the Ceramic Industry-porcelain Stoneware Tiles from Low-impact Raw Materials    
C. MUGONI, M. LASSINANTTI GUALTIERI, D. SETTEMBRE, A.M. FERRARI, C. SILIGARDI, Dept. of Engineering Enzo Ferrari, University of Modena and Reggio Emilia, Italy; Dept. of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, Italy; *Gruppo Ceramiche Gresmalt SpA, Casalgrande (RE), Italy

Critical issues in the ceramic industry are the recovery of ceramic waste and raw materials transportation. European Union (EU) policies are mainly concerned with environmental problems related to the exponential increase of waste. In this context, new EU directives promote waste prevention and recycling through clean technologies and residue management. These directives, together with high disposal costs, currently motivate the ceramic industry to seek recycling solutions of ceramic waste both in the same production system as well as in different ones. Another important issue with economic/environmental impact is the transportation mode and distance. In this study, both waste recycling and transportation were considered when designing a “green” porcelain stoneware tile formulation. In particular, ceramic waste and raw materials arrived by train were used for the novel composition. Samples were obtained by standard powder processing routes and sintering conditions (1200 °C, 45 min). The study was planned using Mixture Design and the measured technological properties were analyzed using statistical methods, in order to define mix formulations potentially classified as BIa. The microstructure of the technologically optimized product was also investigated using analysis techniques.


CM:HP09  Manufacture of Alkali Activated Cements through Mechanochemical Activation from Kaolins with Different Halloysite Content    
I. BALCZAR, T. KORIM, Institute of Materials Engineering, University of Pannonia, Veszprem, Hungary

Alkali activated cements play an increasing role as a successful substitute of ordinary Portland cements due to their superior durability and environment friendliness. Raw materials commonly used for alkali activated cement synthesis are alumino-silicates such as natural pozzolans, fly ashes and calcined kaolins (metakaolin). Present research focused on the manufacture of this novel binding material system based on three kaolins with different halloysite content. The raw materials were activated before setting with two different methods; thermal activation (550, 600, 700 °C) with two chosen heat treatment time (1 h, 3 h) and mechanochemical activation, which is a short, intensive grinding. The grinding time was altered during the experiment, and the physical performance of the obtained mortars were compared. Aim of the investigation was to determine the effect of halloysite content on the reactivity of the thermally or mechanochemically activated kaolin samples. Results indicates that halloysite content has a different effect on the reactivity of the activated kaolin, and thus on the compressive strength results, in the case of thermal and mechanochemical activation.


CM:HP10  Alkali Activated Cement Foam Blends Based on Metakaolinite and Ground Granulated Blast Furnace Slag    
A. BOROS, T. KORIM, I. BALCZAR, Institute of Materials Engineering, University of Pannonia, Veszprem, Hungary

Alkaline activated inorganic polymer foams (AAIPFs), as eco-friendly porous materials, have gain great attention. These materials can be used as catalyst supports in photocatalytic degradation processes. However, the low compressive strength and the shrinkage of the pure foams limit their application potentials. The shrinkage of the AAIPFs can be reduced by the addition of further precursor. In the present study blended metakaolinite-ground granulated blast furnace slag AAIPFs were produced by gelcasting/saponification/peroxide decomposition (GSP) combined method. As an activating component the mixture of NaOH and water glass was used, and sunflower oil and hydrogen H2O2 were added in order for saponification reaction and foaming. The combined foaming process allowed the production of designed porosity AAIPFs. The blended system led to the reduction of shrinkage and an increase in compressive strength. Based on experiments the optimal composition was chosen. Furthermore the relationship between strength and structure was investigated, using FT-IR, XRD and SEM. The organic matter content of the test specimens was monitored by CHNS analysis. The produced AAIPFs can be used as a catalyst support in photocatalytic degradation processes.


CO:HP06  Pathways for Engineering Boron Nitride Nanotube Based High-Strength Metal Matrix Composites    
P. NAUTIYAL, B. BOESL, A. AGARWAL, Plasma Forming Laboratory  Dept. of Mechanical and Materials Engineering, Florida International University, Miami, FL, USA

Boron Nitride Nanotube (BNNT) displays excellent elastic modulus (> 1 TPa) and tensile strength (> 60 GPa), and can survive at elevated temperatures (as high as 1000 °C) without oxidizing or degrading. These brilliant thermo-mechanical properties of BNNT are exploited to develop high-strength and lightweight metal matrix composites based on Aluminum. Very long and fine nanotubes are used as reinforcing nanofiller for superior strengthening. Three major processing routes are adopted: spark plasma sintering (powder metallurgy), metal solidification (casting) and plasma spray (additive manufacturing). BNNTs are found to survive the extreme temperature and pressure conditions involved in these processes. Interfacial chemical reactions, and dispersion and integration of BNNTs in the metal matrix are examined by electron microscopy, X-ray diffraction and energy dispersive spectroscopy. BNNT addition is found to enhance the elastic modulus, hardness and tensile strength of the composite, indicating effective strengthening due to the nanotube. Post failure microscopy shows nanotube pull out and crack-bridging as prominent load-bearing mechanisms. These findings evidence the suitability of BNNT for developing advanced high-performance metal matrix composites for aerospace applications.


CO:HP07  Ablation Mechanism of 3D-Needled C/SiC Composites in Combustion Chamber of Rocket Engine    
CHAO CHEN¹, JIANZHANG LI², XIAOYING LIU¹, BO CHEN¹, JIAMIN WANG², LAIFEI CHENG¹, LITONG ZHANG¹, ¹Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University, Xi’an, China; ²National Engineering Research Center of Ceramic Matrix Composite Manufacture Technology, Xi’an Golden Mountain Ceramic Composites Co., Ltd., Xi’an, Shaanxi, China

The test pieces made from 3D needled carbon fiber felts reinforced silicon carbide composites (3DN C/SiC) were prepared by chemical vapor infiltration process (CVI) and then were evaluated for combustion chamber application in ground test bench of rocket engine. The cylindrical pieces kept the structural integrity after test. Their ablation characteristics behaved uniformly along circumferential directions and varied along axial direction from ablation severity to morphology. The front-end gas in-let part has obvious ablation degradation. However, the majority part, especially the rear part has near zero ablation and was covered by the melt. The composites’ damage originated from thermal chemical ablation of high-temperature rocket engine exhaust and thermal mechanical erosion of multiphase flow gas. The non-steady state and non-uniformity of the multiphase flow field made the partial material endure relatively severe ablation conditions and the introduced impurity elements aggravated such partial ablation of C/SiC.