Strong and ductile metallic thin films through advanced nanoengineering design strategies
Résumé
The current trend toward miniaturization in devices components in key technologies such as micro-/nanoelectronics, energy production, sensors and wear protection requires the development of high-performance nanostructured films with superior mechanical properties. Especially, mutually excluding structural properties such as high yield strength and ductility need to be combined, but also high adhesion with the substrate and large fatigue resistance. In order to trigger microstructure-induced material properties, control of the micro-scale structure, atomic composition, average grain size, and layer/film thickness must be optimized based on nanoengineering design concepts. In addition, measuring the properties of thin films (thickness ≤1 m) requires the development of novel techniques capable to probe their mechanical behavior[1].
Here, I will present recent results for several class of advanced thin film materials including nanostructured metallic glasses (ZrCu, ZrCuAl…)[2-4] high entropy alloys (CoCuCrFeNi, Al/CoCuCrFeNi) and multilayers (fully amorphous, amorphous/crystalline, FCC/BCC)[5], highlighting how the control of micro-structure affect the and micro-scale mechanical behavior and enable ultimate mechanical properties. Special emphasis will also be dedicated to present several cutting-edge techniques used to extract the mechanical/electrical behavior at the micro- and nanometer scale, involving, in situ SEM nanoindentation and micro-pillar compression, and tensile test in situ TEM.
Finally, I will present recent developments within LSPM, highlighting new research activities dealing with the synthesis of nanostructured metallic films and the development of a new platform for in situ SEM mechanical-electrical characterization.