"Advanced experimental methods studying interface failure mechanisms at different length scales"
Interfaces within bi- and multilayered thin film structures are omnipresent in numerous technological applications, yet their susceptibility to premature failure arising from the disparate physical properties of adjacent materials may be critical. Thus, understanding the mechanisms accompanying interface failure is crucial to understand potential toughening and failure mechanisms. Consequently, a thorough investigation into their reliability and an in-depth understanding of the underlying failure mechanisms are indispensable for advancing novel material composites and combinations.
In the first part of the talk, we concentrate on interfacial failure via thin film delamination through newly developed experimental techniques spanning the meso-scale down to the nano-scale, including a detailed stress analysis of the studied film using cross-sectional x-ray diffraction and in situ TEM techniques coupled with nanodiffraction mapping during the thin film delamination process. This approach allows us to understand thin film delamination across various length scales, providing insights into the diverse mechanisms of failure. In the second part, our focus shifts to the fatigue behavior of ductile layers integrated into crystalline-amorphous multilayers, considering the influence of their layer architecture. To investigate these phenomena at the nanoscale, cyclic crack propagation experiments are conducted in situ under the transmission electron microscope, enabling a detailed exploration of crack initiation and propagation across these interfaces. Our comprehensive approach encompasses both the meso-scale and nanoscale, incorporating in situ transmission electron microscopy to capture the mechanisms accompanying interfacial failure. Through this multifaceted investigation, we aim not only to enhance our understanding of interfacial failure via delamination and fatigue. Gaining a deeper understanding in those factors allows to contribute to the development of more reliable and adaptable material systems for diverse technological applications.
