Current research projects

Project Description
Mechanical properties of nanocrystalline metals Nanocrystalline metals exhibit remarkable mechanical properties compared to their coarse-grained counterparts. The underlying mechanisms are still under debate, especially for the smallest grain sizes. In this project in-situ mechanical testing during x-ray diffraction is employed to investigate the evolving microstructure. More
Deformation mechanisms in bcc single crystals A unique combination of micro-compression of single crystal micro-pillars and Laue micro-diffraction is employed to investigate the active slip systems in various body centered cubic metals. More
Heat treatable Al alloys Measurements and modelling of residual stresses during quenching of thick heat treatable aluminium components in relation to their microstructure. More
Nano-silver as bonding material Investigate the microstructure and thermo-mechanical properties of nano porous sintered polycrystalline Ag layers using various techniques including in-situ x-ray diffraction, nano-tomography, ptychography and electron microscopy. A 3D microstructure based simulation is applied to allow a better correlation between the porous morphology and mechanical behavior. The outcome of these experiments will be used to generate a lifetime prediction model for sintered die-attachments.
Cyclic plasticity in shear Understand the evolution of dislocation patterning occurring in the earlier phases of fatigue before the saturation stage is reached. Crystal rotation caused by the emerging dislocation structures and GND density distribution are analyzed in fcc single crystals. This is done with Laue diffraction during in-situ reversed-shear deformation at the microXAS beamline of the Swiss Light Source. For achieving this purpose a new miniaturized shear device and designed suitable sample geometry have been developed. The project is part of a collaborative project titled “Constitutive modelling and microstructural validation for crystal plasticity finite element (CPFE) computation of cyclic plasticity in fatigue” (SNF – 138240).
POLDI detector upgrade Development of a ZnS/6LiF scintillation detector for simultaneous measurement of axial and transverse strain in collaboration with the detectors group and the electronics and measuring systems group. More

Finished research projects

Project Description
Bottom-up Laue diffraction Calculation of Laue diffraction spots from dislocation ensembles simulated by dislocation dynamics. More
Development of residual strain in bainitic steel The accumulation of residual strain during room temperature and high temperature deformation of a 1%CrMoV steel is studied by advanced in-situ x-ray and neutron diffraction techniques.
Microstructure of single crystal Ni-based superalloys The aim of this project is to obtain profound understanding on the influence of plastic deformation on the microstructural changes observed in single crystal Ni-based superalloys using diffraction techniques.
The color of Gold With an ever-growing interest in the luxury industry for innovations, the development of new colors in precious alloys has become of strategic importance as a major differentiating factor for brands. However, the development of innovative alloys, featuring new colors by addition of non-classical alloying elements is tedious and expensive if large empirical screenings of compositions have to be executed. This project addresses this issue by ab initio modeling effort for color prediction More
Atomistic simulations of nanocrystalline metals The investigation of the influence of the triple junctions and the accommodation processes in the surrounding GBs on coupled grain boundary motion More