EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

X-ray micro tomography allows non-destructive imaging of the internal microstructure of materials, with a spatial resolution that can approach that of optical microscopy. This technique is gaining more and more importance for applications where the three-dimensional (3D) nature of the phenomenon is important, or when the evolution of critical characteristics is of interest, whether in the...

For a decade, modern synthesis methods, such as severe plastic deformation, were developed and applied on metallic lamellar composites in order to reduce their layer width to less than 100 nm. Nowadays, these new nanostructured materials then offer outstanding mechanical properties which are partly attributed to the role increasingly played by interfaces in their plastic behavior. This role is...

The biaxial modulus is an important elastic property of thin films and coatings. A state of equi-biaxial strain does not generate equi-biaxial stresses in anisotropic materials and hence different biaxial moduli are defined under these cases. Thin films and coatings generally possess a fibre-texture. As the biaxial modulus is anisotropic, polycrystalline averages are used. The Voigt and Reuss...

Nano-multilayers (NMLs) represent an important class of nano-architectured materials which find numerous applications in the fields of microelectronics, optics and sensing devices. The presence of (high) residual stress resulting from the multiple interfaces, epitaxy, grain boundaries and impurities gives rise to mechanical and thermal technological challenges in NMLs. Stability and...

Data management is crucial in the scope of material science digitalization and collaborative research projects. In this context, a simple modular workflow is proposed to link material properties databases with analytical and numerical modelling tools. As a first step, Ansys Granta MI framework is used and designed to capture and to manage a large amount of experimental data [1]. Then,...

Double-cantilever beam experiments are developed to measure the bonding energy in wafer-bonded semiconductors. The comparison is carried out in two material combinations relevant to microelectronics and silicon photonics: Si on an insulator and InP on Si. Although the two implementations differ in the scale of the measured sample area, the measurement conditions, and the step in the...

Due to an outstanding combination of hardness and toughness, the WC-Co hard metal is successfully used in many applications and is considered one of the most important composites in engineering. Nevertheless, recently there has been significant advances achieved in its performance as micromechanical tests have facilitated a better design. A particularly useful technique applied to the WC-Co,...

Piezoresistive soft composite materials are widely used in strain sensing and typically exhibit a decrease in conductivity upon elongation—the so-called positive gauge effect. We demonstrate a thin-film architecture that features the inverse behavior: a strain-induced transition from insulating to metallic conductivity, spanning nine orders of magnitude in conductivity. Our approach is based...

Key Words: EBSD; GBCD; DCB; Fracture; Energy; Carbide Boundaries

Cemented carbides (WC-Co) are an important class of tool materials in the manufacturing industry, with applications in mining, drilling and cutting. Their unique composite structure consists of two interpenetrating constituent phases: hard tungsten carbide particles and softer cobalt binder. This results in a unique...

Nanoindentation (NI) is a contact method to investigate localized micromechanical properties of materials. The main advantage of NI compared to macroscopic mechanical test methods is the easy sample preparation. Also processing-related influences on mechanical properties are considered accordingly. NI of semi-crystalline polymers is a special challenge. The influence of morphological...

Bronze alloys, i.e. Cu-Sn alloys, exhibit up to nine different phases according to the phase diagram. Although known for decades, those phases are barely mechanically investigated. Thus, in this work, a Cu 20 m.% Sn alloy was intensively investigated with various experimental techniques to gather the existing knowledge about the Cu-Sn system with a particular focus on the properties of the...

The modification in the dimensions of a material leads to changes in its properties, especially the mechanical properties. In recent years, it has been shown that nanotwinned metals have two mechanical properties that are usually antagonistic, namely high yield strength and good ductility [1]. We performed tensile tests on gold thin films with nanotwins, in-situ under X-ray diffraction [2]. ...

To mitigate mechanical failures of semiconductor devices it is necessary to understand the underlying damage mechanisms. Especially important is the identification of the damage initiation location to identify the mechanically most fragile areas. Due to feature sizes of less than 100 µm, a micromechanical approach utilizing a nano indenter system had to be applied in this work. The experiments...

Microlattices are an emerging class of metamaterials combining desirable mechanical properties like high specific strength, ductility and energy absorption. Two-photon lithography (TPL) is a promising nanofabrication technique that allows producing structures up to the millimeter scale with submicron resolution. Here, we aim at 3D printing and characterizing miniaturized structures at...

Fibre-reinforced composites have been proposed for a range of applications, including deep-sea pipes. The tensile properties and strength to weight ratio of these composites is advantageous compared with classic materials. However, the compressive properties of such composites are poorly understood and difficult to quantify. Compression testing indicates substantial interfacial failure between...

Zirconium alloys are used as fuel cladding materials in water-based nuclear reactors, where hydrogen pick-up results in the formation of brittle zirconium hydride packets which degrade the material’s mechanical performance. In situ scanning electron microscope (SEM) compression tests of hydride-containing micropillars with controlled orientations are employed to understand the anisotropic...

Nanoindentation techniques are widely used leading to a variety of different mechanical designs and hardware-software concepts. They have a huge influence on the realization of experiments. Constrains are due to price and time budget limitations for testing, technical limitations, software options and user support.
The sm@rt 500 nanoindenter is designed to offer a versatile testing...

The shape of the indenter at its tip can significantly affect the results of indentation measurements especially for indentations at low depths. Indenters are inevitably blunted during their use, namely when indenting hard materials. Although some bluntness can be corrected by the calibration of the indenter area function, it is advantageous to know the tip radius since that will tell the user...

Layered ceramics are present in many applications and environments such as geology, energy storage or nuclear energy. Their layered structure results in a material with stronger in-(basal)-plane than out-of-plane ({0001} basal plane) bonds. This results in a strong surface energy anisotropy which is employed for instance to promote toughening in structural components but also as a way of...

We examine the behaviour of short and long polymers of polyvinyl alcohol by means of coarse-
grained computer simulations. In particular, we focus on the structural changes on the monomer
and polymer scale during cooling and the application of uni-axial true-strain. The straining of
long polymers results in the formation of a semi-crystalline system at temperatures well above...