High-throughput nanoscale mechanical property mapping under high temperature and high vacuum environment

摘要

Materials development for next-generation alloys in critical applications requires high-throughput methodologies. This is due to the number of alloy permutations, processing routes, and operando conditions to be evaluated. Nanoindentation can provide statistical datasets at length scales that allow not just macro behaviour, but behaviour at microstructural length scales to be evaluated. A new nanomechanical test system, capable of elevated temperature testing under vacuum, enables mechanical mapping of oxidation sensitive materials. As a demonstration of the system's capabilities, a dual phase FeNiCoCrMnAl_(0.3) high entropy alloy is evaluated which is an alloy of interest for nuclear applications owing to its potential to absorb substantial radiation defects. We correlate the mechanical maps made via nanoindentation with crystallographic maps made via electron backscatter diffraction. We also explore the automatic assignment of indents to the two phases using machine learning clustering techniques with reasonable success. This alloy is found to have stable mechanical properties in the temperature range evaluated, which will prompt further studies at higher temperatures and under simulated radiation damage.