Symposium CD
Joining of Inorganic Materials: From Macro- to Nano-length Scales

Session CD-1 - Nano-scale Interface of Dissimilar Materials

CD-1:IL01  New Cu / Ceramics Bonding Technology for Highly Reliable Power Module Substrates
YOSHIYUKI NAGATOMO, NOBUYUKI TERASAKI, YOSHIROU KUROMITSU, Mitsubishi Materials Corporatin, Central Rearch Institute, Saitama, Japan

At present, active metal brazing (AMB) substrates, in which Cu is bonded to a nitride ceramics such as AlN by using Ag - Cu - Ti system as an bonding material, are widely used for power modules. The AMB substrate has a feature of excellent insulating property and is used for applications requiring high withstand voltage such as for electric train. However, the problem of migration of Ag in use under higher voltage is pointed out. Therefore, we focused on Cu - P - Sn - Ti system as a bonding material substituting for the conventional Ag - Cu - Ti system and investigated to apply it to the bonding between Cu and nitride ceramics. As a result, the new bonding method using Cu - P - Sn –Ti system can achieve remarkable lower bonding temperature than that of the conventional Ag - Cu - Ti type, and further, Ti – O layer is formed at the interface instead of TiN which is formed in conventional AMB as a reaction layer. It was shown that the reliability of the new AMB substrate manufactured under the condition that the Ti - O forming reaction sufficiently occurs is equivalent to the conventional AMB substrate in thermal cycling tests. It is considered that the new AMB substrate using this new bonding technology can be useful for practical applications sufficiently.


CD-1:IL02  Interface Engineering of Nanostructured Joining Materials
L.P.H. JEURGENS, B. RHEINGANS, M. CHIODI, V. ARAULLO-PETERS, C. CANCELLIERI, J. JANCZAK-RUSCH, Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Joining Technologies & Corrosion, Duebendorf, Switzerland

With the continuing miniaturisation of devices and sensing components, typical dimensions of interconnections and integrated components have crossed the micro-scale and entered the nano-scale. Hence novel joining concepts are required to integrate, package and assemble dissimilar and heat-sensitive materials at ever-lower temperatures with a precision down to the nano-scale. This talk addresses recent developments and applications of nanostructured joining materials for emerging micro- and nano-joining technologies. The development and application of nano-structured foils and coatings for reactive joining of a wide variety of dissimilar materials at room temperature in air is reported. The crucial issue of managing the heat flux from the exothermic reaction into the solder, metallization and base materials will be exemplified. Furthermore, novel nanobrazing technologies on the basis of nano-multilayered fillers will be highlighted, which exploit the melting-point depression of nano-confined metals in combination with short-circuit diffusion to achieve ever-lower joining temperatures. It will be demonstrated that the engineering of hetero-interfaces in such nanostructured joining materials constitutes a crucial step to tune their phase stability and reactivity.


CD-1:IL03  The Temperature and Time Dependence of Nanoscale Chemical Reactions at Brazed Alumina Joints
P.M. MALLINSON, AWE Plc, Reading, UK, M. ALI, K.M. KNOWLES, University of Cambridge, UK

The interfacial phases formed during active metal brazing (AMB) are one of the key factors in manufacturing a high quality joint. Previous studies have identified a bi-layer at the braze-alumina interface consisting of Ti3Cu3O and γ-TiO; however the evolution of these phases during the process has not been fully investigated. Additionally, during AMB of the Kovar alloy (Fe-29Ni-17Co, wt%) to alumina, reactions between the braze and the Kovar have been reported to occur. Although how this affects the chemical reactions at the alumina-braze interface was not clear. In order to determine how the AMB reactions proceed and are affected by time and temperature, Ag-Cu-Ti active braze alloys have been used to produce a range of alumina-alumina and alumina-Kovar joints. The quality of these joints was assessed in terms of hermeticity and tensile strength. Scanning and transmission electron microscopy has been used to characterise the microstructures. Initially a transient Ti2O layer was found to form at the alumina-braze interface, this then breaks down to form the Ti3Cu3O layer with the γ-TiO layer forming last. For the alumina-Kovar joints the intrinsic chemical reactions were found to be the same only to a lower extent, due to the reaction of the Ti from the braze with the Kovar.


CD-1:IL04  Defining Hetero-epitaxial Relationships of Films on Substrates
D. CHATAIN, CINAM, Aix Marseille Univ, CNRS, Marseille, France; P. WYNBLATT, A.D. ROLLETT, MSE, Carnegie Mellon University, Pittsburgh PA, USA; U. DAHMEN, NCEM-Molecular Foundry, LNBL, Berkeley, CA, USA

The orientation relationship (OR) of a thin film on a single crystal substrate is essential for a fundamental understanding of the factors that control thin film growth and texture. Several parameters (lattice constants, elastic constants, interfacial energies, etc.), drive the OR, and most of the discussion concentrates on the role of terraces, steps and defects to accommodate structural differences or lattice mismatch across the hetero-interface between the two abutting phases. The different definitions for the heteroepitaxial relationship at an interface depend on whether the interface is considered from a surface science, a phase transformation or a grain boundary perspective. In this talk, we will use examples of the silver on nickel and of the copper or nickel on sapphire to illustrate these different approaches and propose an optimal choice for defining an OR.


CD-1:L05  Wetting and Brazing of Vitreous Carbon by Reactive Ag-Cu-In-Ti Alloys
M. TAZI, V. CHAUMAT, Univ. Grenoble Alpes, CEA, LITEN, DTBH, LCA, Grenoble, France; F. HODAJ, Univ. Grenoble Alpes, CNRS, Grenoble INP, SIMAP, Grenoble, France

The use of reactive alloys with low melting point for brazing of vitreous carbon, allows decreasing of internal constraints during cooling and thus the brazing of large pieces of carbon. Ag-Cu-In-Ti alloys belong to this class of alloys with a melting point of 600-700°C. However, the kinetics of interfacial reaction and spreading of these alloys on carbon are not known. The aim of this work is to study the wetting and brazing of carbon by these alloys. Wetting experiments were carried out at 770-920°C under high vacuum using sessile drop method. The morphology and composition of the reaction layer were characterized by scanning and transmission electron microscopy and energy dispersive X-ray spectroscopy. Low contact angles are obtained at above 770°C but no wetting is reached below this temperature. The spreading kinetics strongly depends on the temperature and the mechanisms that control the spreading process were determined. Brazing experiments in C/C (homogeneous) and C/metal (heterogeneous) configurations were performed at 800-900°C under high vacuum for 5 to 30 min. The microstructures of the joint and reactive interfaces were characterized. Mechanical tests were performed in order to determine the experimental parameters leading to a good mechanical behavior of the joint.


CD-1:L06  Effect of Point Defects on Interfacial Bonding Between Noble Metal and TiO2(110) Surface
KATSUYUKI MATSUNAGA, Department of Materials Physics, Nagoya University, Aichi, Japan; Nanostructures Research Laboratory, Japan Fine Ceramics Center, Aichi, Japan

Metal atoms and clusters on oxide surfaces have attracted much attention in the field of catalysis. It is thought that interfaces between metal and oxide surface affect catalytic activity, and thus it is important to reveal detailed electronic and atomic structures of the interfaces. In this study, electronic and atomic structures of single Au and Pt atom adsorption on rutile TiO2 (110) surface were investigated by density functional theory (DFT) calculations, together with experimental scanning transmission electron microscopy. It was found that Pt adsorption takes place at basal oxygen vacancies as well as at bridging oxygen vacancies of the surface. However, Au atoms tend to adsorb only at the bridging oxygen vacancy sites. Such a difference between Pt and Au arises from characteristic electronic structures of the oxygen vacancies as well as characters of outermost atomic orbitals of Au and Pt.


CD-1:IL07  Reactive Wetting and Filling of Nanotubes by Molten Metals to Design Advanced Nanocomposites
P. NAUTIYAL, B. BOESL, A. AGARWAL, Plasma Forming Laboratory, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL, USA

Boron Nitride nanotubes (BNNT) are gaining tremendous attention, as they display a unique combination of extraordinary mechanical strength, stiffness, flexibility and energy dissipation ability. Integration of BNNTs in the metal matrix is a promising approach for designing composites with superior mechanical properties. The development of these advanced composites is dependent on the physical and chemical interactions between the ceramic (BN) and metallic phases. As metal solidification is the most popular commercial manufacturing process, the nanotubes should be able to survive the reactive conditions involved in melting of metals. Additionally, it should be adequately wetted by the molten metal for the development of strong interface to facilitate effective stress transfer in the composite. We explored interactions between molten Aluminum and Boron Nitride Nanotubes (BNNT). These nanotubes were found to survive and retain their tubular morphology post solidification in the Aluminum matrix. Microstructure investigation revealed limited interfacial reactions, resulting in the formation of AlN, AlB₂ and AlB₁₀ phases in trace amounts. Formation of interphases facilitates the joining of nanotubes with the metal matrix due to covalent bond formation. AlN is the principal reaction product, making a thin layer on the nanotube wall. Theoretical calculations show improved work of interfacial adhesion due to AlN formation. As the nanotubes have extremely fine diameter, they were found to exhibit capillary effect, resulting in the filling of BNNT by molten Aluminum during solidification processing. Limited chemical reactions were noticed inside the nanotubes, resulting in unique core-shell structures and multiple nano-ceramic phases in the metal matrix. These findings clearly show the diversity that can be accomplished in designing nanocomposite microstructures by employing ceramic nanotubes.


CD-1:IL08  Atomic-scale Structural and Chemical Analysis of Heterointerfaces by Advanced Scanning Transmission Electron Microscopy
A. KUMAMOTO, N. SHIBATA, YUICHI IKUHARA, Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Tokyo, Japan

In recent years, atom-resolved chemical mapping becomes possible by combing aberration-corrected STEM and energy dispersive X-ray spectroscopy (EDS). STEM-EDS analysis makes it possible to determine almost all the element atoms in periodic table at the same time, so it is advantageous to characterize complex materials and devices with local chemical inhomogeneities. In this study, we applied this technique to resolve complex local chemical structures at bimetallic catalytic particles and metal-ceramic heterointerfaces (Al alloy-AlN). By using an aberration-corrected STEM with high-sensitive silicon drift detectors (SDD), atomic-scale chemical distribution of both heavy (metals) and light (oxygen or nitrogen) element atoms across the interfaces can be clearly mapped. We demonstrate such chemical analysis elucidates the important roles of impurity atoms for the stable formation of heterointerfaces. Thus, the atom-resolved STEM-EDS mapping should open a new avenue for characterizing very complex interface structures in many materials and devices in addition to the conventional STEM imaging methods such as high-angle annular dark field (HAADF) and annular bright field (ABF) imaging. In this talk, details of such ultrahigh-resolution chemical mapping will also be reported.


CD-1:L09  Ionic Interdiffusion as Interaction Mechanism of Al and Si3N4
E. ADABIFIROOZJAEI¹, F. EMADI², P. KOSHY¹, C.C. SORRELL¹, ¹School of Materials Science and Engineering, UNSW Australia, Sydney, NSW, Australia; ²Department of Materials Science and Engineering, Sharif University of Technology, Tehran, Iran  
 
Controlling the interaction of metals and ceramics necessitates the knowledge of the interaction mechanism. In spite that the interaction for Al-Si₃N₄ has been investigated previously, but the interaction mechanism is still unknown. In the present work, Al-Si₃N₄ couples were prepared and heat-treated at four different temperatures (850°-1150°C) for 250 hours. The thickness of the resultant interacted area was measured by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). According to the results, the interaction constant (K in X=Ktⁿ) increases exponentially with the temperature inverse (1/T) as K=5×10^-9exp(-194.23/RT) (m²/s). This indicates that the interaction is diffusion dependent with diffusion pre-coefficient of 5×10^-9 m²/s and activation energy of 194.23 kJ/mol. The interfacial area also has been analyzed by TEM and results showed that the interfacial area is composed of AlN grains, Al channels and Si precipitates.  Also, it was observed that there is a topotactic relationship between the intact Si₃N₄ grains (the reactant) and the AlN crystallite (the product) crystals.  According to kinetic data and high resolution TEM data it is concluded that Al³⁺-Si⁴⁺ interdiffusion through a series of solid solution phases at the interface of intact Si₃N₄ grains and AlN crystallites controls the interaction.

 
Session CD-2 - Micro-/Nano-joining

CD-2:IL02  Metal-to-ceramics Joining using Reduction Reaction of Silver Oxide
AKIO HIROSE, K. ASAMA, K. MOTOYAMA, T. SANO, T. MATSUDA, Osaka University, Suita, Japan

The authors have proposed low-temperature sintering joining techniques using nano-scale Ag particles as a filler material. After joining the joint has superior heat-resistance properties coming from the high melting point of sintered Ag layer. Thus, the joining processes using nanoparticles have been developed as alternative to soldering using Pb-rich high-temperature solders. To improve the bondability more, and also to reduce the cost of the filler material, a new bonding process using Ag2O paste consisting of Ag2O particles mixed with a reduction solvent has been proposed. In this joining process, Ag nanoparticles formed through the reduction of Ag2O at a low temperature are immediately sintered to one another and bonded to a substrate material. Au, Cu and Al have been successfully joined using the Ag2O paste. In the present study the joining process has been applied to joining of ceramics. The Al2O3 specimen was successfully joined to the Au coated Cu disc through a sintered Ag layer using the Ag2O paste. With increasing bonding temperature and bonding pressure, sintering of Ag layer progressed and thereby the joint strength significantly increased. The Al2O3 to Ag direct joining was successfully achieved by sintering of Ag particles. At the Ag/Al2O3 interface, the Ag layer.


CD-2:IL03  Development of Nanostructured Joining Materials
J. JANCZAK-RUSCH, M. CHIODI, V. ARAULLO-PETERS, C. CANCELLIERI, L.P.H. JEURGENS, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland

Nanostructured joining materials are developed to exploit short and fast diffusion paths along surfaces and interfaces in nanoconfined materials for the micro- and nanotechnology applications. The materials are deposited by magnetron sputtering techniques and consist of alternating nanolayers of a metallic material (Ag, Cu, Ag-Cu, Al, Al-Si) and a chemically-inert ceramic barrier material (e.g. nitride, oxide). With the aim to understand the elevated temperature behavior of these materials, Ag/AlN and Ag-Cu/AlN nanomultilayers (NMLs) in various configurations were studied by combining HR-SEM, TEM, ex-situ and in-situ XRD, Auger Electron Spectroscopy methods. The effect of the NML design, the internal interfaces and stresses on the NML behavior is discussed. In particular, it was found that the thickness and microstructure of the ceramic nanolayers play a significant role when controlling the melting and diffusion behavior of the nanoconfined metallic material. The results show that it is possible to trigger fast mass transport of the nanometal to the bonding surface even at low temperatures. Thus the nanostructured joining materials might open new opportunities for the development of fast, low-temperature or localized, selective joining methods.


CD-2:L04  AE Evaluation of GaN Die-attach on DBC Substrate
CHANYANG CHOE, S.J. NOH, C. CHEN, S. NAGAO, K. SUGANUMA, The Institute of Science and Industrial Research, Osaka University, Osaka, Japan

Wide band-gap devices such as GaN, attached on direct bond copper (DBC) in power electronic, are expected to be used at high temperatures between 200 ∼ 300 ºC. Such severe thermal cycling environment sometimes causes fractures resulting in strength deterioration of die-attach structure. Acoustic emission (AE) is an excellent method to evaluate material damages. In this work, AE was applied to evaluate failure of GaN die-attach on DBC substrate during thermal cyclic exposure for the first time. A GaN die was attached on DBC substrate at 250 ºC using our original hybrid Ag sinter paste. Thermal cycle test was carried out on the joint structure by using a specially designed heating element. AE signals were detected by a wide band acoustic sensor. Strength deterioration and microstructural variation of die-attachment on DBC substrate was also evaluated. Shear strength was decreased with number of thermal cycles, while the cumulated AE signal was increased. The micro-cracking was observed and increased gradually during thermal cycling. The relationship among strength degradation, the observed crack and AE signal was confirmed. Based on these result, a feasibility of AE mentoring the die-attachment failure was well demonstrated.
This work was supported by the JST ALCA project.


Session CD-3 - Macro-joining

CD-3:IL01  Wettability-induced Change in Crystallization Behavior of Supercooled Liquids Composed of Li2O-SiO2
SOHEI SUKENAGA, M. TASHIRO, H. SHIBATA, IMRAM, Tohoku University, Sendai, Japan

Following phase diagram, crystalline lithium disilicate (Li2Si2O5, LS2) materials, which have excellent mechanical properties, should be obtained efficiently through the crystallization of supercooled liquid composed of LS2. However, in addition to LS2, a lithium monosilicate (Li2SiO3, LS) phase is also precipitated during the crystallization of the liquid. The precipitation of the LS phase makes it difficult to obtain a single-phase LS2 material. In this study, it is shown that by altering the oxygen partial pressure or contact materials, it is possible to change the selectivity of the precipitated phase by using the interfacial phenomena that occur between the liquid and contact material. During cooling of the supercooled liquid, the type of precipitated phase can be changed by altering the atmosphere and type of contact material. This technique can be applied for the fabrication of other functional materials and does not require the use of other additives.


CD-3:IL02  Crack Paths in Layered, Graded Joints
I. REIMANIS, Colorado School of Mines, Golden, CO, USA

This paper reviews the prediction of crack paths in layered materials where the composition, microstructure or properties are graded. For most situations, the prediction of failure requires a priori knowledge of the crack path, and in many cases, a crack kinking criterion is sufficient. However, in some cases the crack path is intimately connected to the failure criterion. The presence of residual stresses due to thermal expansion mismatch typically plays a major role in the determination of crack path and hence the crack driving force. Examples are provided that demonstrate relevance to the strength of joints.


CD-3:L03  Homogeneous Diffusion Bonding of ZrCx: Empirical Evidence and Phase Field Modeling 
RUI PAN^{1, 2}, S. KOVACEVIC³, D.P. SEKULIC^{1, 2}, S.DJ. MESAROVIC³, ¹University of Kentucky, Lexington, KY, USA; ²Harbin Institute of Technology, China; ³Washington State University, USA

Empirical evidence of forming a homogeneous ZrC diffusion bonding joint is presented. ZrC_x ceramics were diffusion bonded using a transition metal (M) as an interlayer. The mass transport across the interfaces was promoted by an increase in the concentration of carbon vacancies within the base ceramics. When using a 10 μm thick Ti interlayer, homogenous joint domains were formed in ZrC_0.7 joints, however, homogenous joint domain could not be formed in the case of a stoichiometric ZrC. To uncover the reason behind this phenomenon and to predict the microstructure, numerical simulations of ZrC_x diffusion bonding were carried out. The phase-field model including bcc, hcp and B1 phases of metal and metal carbide, as well as the effects of compositional and thermal mismatch internal stresses in the joint and the surrounding material, is implemented into the finite element framework. The effects of: carbon vacancy concentration in ZrC_x, the peak temperature level and dwell time, the interlayer thickness, and phase transformation strains, are discussed. It is shown that the formation of a homogenous domain improves remarkably the mechanical properties of ZrC_x joints. The bending strength, as well as the nano-indentation hardness of the homogenous ZrC_x/M/ZrC_x joints, can be as high as for the one of the base ceramics.
 

CD-3:IL04  Joining of UHTC Composite using Powder-based Metallic Interlayer
NORITAKA SAITO, KUNIHIKO NAKASHIMA, Kyushu University, Fukuoka, Japan

Ultra-high temperatures ceramics (UHTCs) are the subject of intense worldwide research effort, and their stability in severe environments makes them candidates for aerospace, nuclear and solar energy applications. Widespread usage UHTCs requires the development of effective and reliable joining methods that facilitate the fabrication of large, complex-shaped, and potentially multimaterial components and devices. Joining of ZrB2 composite that exhibits outstanding thermo-mechanical and thermochemical properties and good erosion and corrosion resistance, was the focus of the present study. ZrB2–10vol%MoSi2 composite was joined at 1500 °C with Ni-ZrB2 powder-based interlayers, which can provide us more rapid interfacial reaction of TLP interlayer because of surface area that could be involved into the intensive reaction. No void and crack were observed at the interface region, which indicates the joining of ZrB2 composite have successfully done. The four-point bending test on the joints revealed 660±84.6 MPa at the room temperature, besides 377±77.0 MPa for the ZrB2 composite itself, which suggests the Ni-ZrB2 interlayer enhances the strength of the composite joints. Additionally, the joints were oxidized at 1500 °C for 6 h under air condition, then the four-point bending strength of oxidized joints was measured. The four-point bending test of the oxidized joints revealed 625±38.6 MPa, which indicates the Ni-ZrB2 powder-based interlayer maintained the strength of the joints even after the oxidation process.


CD-3:IL05  The Role of Wetting in Joining
D.P. SEKULIC, College of Engineering, University of Kentucky, Lexington, KY, USA; School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, China

This invited lecture offers a review of the role of wetting in joining by brazing through the discussion of the phenomenology of the joint domain formation of similar and/or dissimilar materials. A comprehensive approach to the identification of criteria for an assessment of the successful design of a joint will provide a context within which the role of wetting will be emphasized. Empirical data, obtained by an in situ and in real-time visualization of the triple line movement will illustrate both wetting and non-wetting systems. Special emphasis will be given to the modeling of the kinetics of the triple line movement during the liquid metal wetting (both advancing and receding spreading). Modeling of spreading will be considered at the macro/micro scale using non-sharp boundary methods of phase-field diffuse interface approximations.


CD-3:L06  Mechanical Property of Dissimilar Metal Joints made by Friction Stirring
MASAHIRO FUKUMOTO, TOSHIAKI YASUI, Toyohashi University of Technology, Toyohashi, Japan

Fabrication method for high performance dissimilar metal joint has been established in our research group by using friction stir welding. 100 % joint efficiency was given by the method in the welded joint between normal steel and Al alloy by adjusting tool offset into an appropriate value. Fe2Al5 intermetallic compound, IMC, layer with 300 nm thickness was observed at interface between both materials. It is believed that the thickness of the IMC layer at interface is a key factor to decide the mechanical property of the joint. However, any quantitative, reliable relationship between IMC layer thickness and the mechanical property of the joint has been verified up to today. This study aimed to evaluate the mechanical property of the dissimilar metal joints made by the friction stir welding systematically. The results obtained showed that the mechanical strength of the welded joint proportionally decreased with increase of the IMC layer thickness over 1 micron meter thickness range. Less than 1 micron meter thickness range, on the other hand, the strength of the joint had almost constant value. By heating the joint at 723 K, fraction of Fe2Al5 in IMC layer at interface seemed to increase with heating period. However, the clear relation between fraction of Fe2Al5 and mechanical strength of the joint was not verified. More precise observation should be carried out in the future study.


Session CD-4 - Application Engineering

CD-4:IL01  Importance of Chemical Exchanges between Matrix and Reinforcement during Synthesis of Metal Matrix Composite
O. DEZELLUS, J. ANDRIEUX, B. GARDIOLA, Laboratoire des Multimatériaux et Interfaces, Université Lyon 1, Villeurbanne, France

In the general context of structural lightening, Metal Matrix Composites (MMC) have attracted much interest over the past decades because of their high specific mechanical properties compared to existing metallic alloys. Powder metallurgy route is the most widely used technic for the synthesis of MMC materials. Whatever the nature of the matrix alloy, a high temperature treatment is necessary in association with the final consolidation step to ensure full densification of the material. During such high temperature treatment, chemical exchanges between matrix and the TiC particles used as reinforcement could occur with some significant and even drastic impact on the final properties of the composite. In this presentation, the case of Fe and Ti metal matrix composites reinforced by TiC particles will be reviewed. The nature of the exchanges and or reactions between matrix and reinforcement has been studied from the thermodynamic point of view. Moreover some kinetics aspects have also been experimentally studied, including in-situ diffraction at ESRF. Finally, in the specific case of Ti matrix a complete thermo-kinetic modelling of interaction is proposed, allowing prediction of some important microstructural parameters during the high temperature heat treatment step.


CD-4:IL03  Torsion Shear Testing of Ceramic Joints for Components Design
J. KUEBLER, G. BLUGAN, G. MATA-OSORO, Empa, Swiss Federal Laboratories for Materials Science and Technology Laboratory for High Performance Ceramics, Duebendorf, Switzerland

Joining of materials and especially dissimilar materials is a powerful tool to produce novel components with improved properties. The goal is to accumulate and enhance the positive characteristics of the individual materials in a single part, e.g. lightweight while avoiding of rivets and screws. For such components the acceptable torsional shear strength is often design relevant. Therefore, a correct mechanical characterization is essential, but is not always straightforward. To measure shear countless lap shear standards are available - but all of them have the problem that effectively apparent shear strength is measured which is influenced by sample geometry, mixed stresses in the joining area or cleaving the samples instead of shearing them. In other words, they all measure a technological property instead of a materials property. Overall, only torsional shear (and asymmetric 4-point-bending-) tests can produce pure shear stress in the joining area and deliver design relevant values. Therefore, in the frame of FP7 project ADMACOM, we developed a torsional shear test which also can be used from low to high temperatures and even for cyclic loading as such conditions are specifically relevant for aero and space applications.