Plasticity, fatigue, and fracture of materials are usually initiated by local deformation processes. Detecting and understanding the underlying mechanisms is the key to improve the mechanical performance and lifetime of miniaturized materials and also of macroscopic materials. Many advanced structural materials possess complex multiphase microstructures where the mechanical interplay of the different phases and their interfaces is poorly understood. Similarly, functional materials employed in modern micro and nano-technologies are composed of material stacks and/or of different phases and possess confined geometries such as thin films, lines, rods, etc.. Such micro- or nanosized materials often show a completely different mechanical performance compared to their bulk counterparts as a consequence of confinement effects. The mission of the Department Structure and Nano-/Micromechanics is
· to develop experimental methods to perform quantitative nano-/micromechanical and tribological tests for complex and miniaturized materials,
· to unravel the underlying deformation mechanisms by advanced microstructure characterization techniques from the micrometer level down to atomic dimensions,
· to establish material laws for local and global mechanical behavior, and finally
· to generate nanostructured materials and high temperature intermetallic materials with superior mechanical properties.
The in-depth microstructure investigations include atomic resolved high-resolution transmission electron microscopy (TEM), analytical and conventional TEM, scanning electron microscopy with electron backscattered diffraction (SEM/EBSD), focussed ion beam microscopy (FIB), X-ray diffraction and synchrotron radiation techniques. A cornerstone will be the combination of advanced characterization and mechanical testing in form of in situ nano-/micromechanical experiments which will permit to simultaneously observe the microstructural changes while measuring the mechanical response. The gained insights will be used to quantitatively describe and predict the local and global material behavior and to design superior nanostructured materials and high temperature intermetallic materials by using local confinement effects. The synthesis of miniaturized nanostructured materials will be done by molecular beam epitaxy.