Combinatorial Mechanical Investigation of Thin-Film Alloys Through High-Throughput Membrane Deflection Experiment

Advanced multi-component alloys, such as bulk metallic glasses and high entropy alloys, exhibit outstanding mechanical properties. Phase formation and physical properties of such material systems depend largely on their chemical compositions. Vast composition ranges, therefore, need to be investigated to discover novel multi-component alloys with enhanced mechanical properties. In this work, we propose an experimental technique that combines combinatorial synthesis and a high-throughput mechanical testing method to efficiently carry out tensile testing for a broad range of metals and alloys. Si-based microfabrication processes, as well as the combinatorial magnetron sputter deposition process, were used to fabricate freestanding tensile specimens of thin-film alloys with composition spreads. The membrane deflection experiment (MDE) has been used to determine the thin-film alloys' stress-strain curves. A 3-axis indentation system with reasonable force and displacement resolutions (5 nm, 60 nN for displacement and force) has been built and utilized for the MDE. A vision-based control scheme was integrated into the system to automatically align the indenter tip to a specific position of the sample. Details of the experimental technique and some results on combinatorial thin-film alloys will be shared.