|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Advances in Multi-Principal Elements Alloys X
||In-situ 4D-STEM imaging of the synergistic deformation mechanisms responsible for the fracture resistance in CrCoNi
||Yang Yang, Sheng Yin, Qin Yu, Ruopeng Zhang, Mark Asta, Robert Ritchie, Andrew Minor
|On-Site Speaker (Planned)
High- and medium-entropy alloys (HEAs and MEAs) have shown excellent fracture toughness, especially under cryogenic temperatures. It was previously shown by in-situ TEM that a synergy of multiple deformation mechanisms including dislocations and twinning is responsible for such outstanding mechanical performance. On the other hand, the existence of chemically local ordering, i.e., short-range-order (SROs), has recently been directly imaged by multiple research groups. However, the interplay between SROs and the mechanical performance in HEAs and MEAs still remains unclear. Here, we applied a new technique, namely in-situ four-dimensional scanning transmission electron microscopy (in-situ 4D-STEM), to study the mechanical deformation in CrCoNi MEA at nanometer resolution in real-time. We directly probed the critical role of SROs on the tuning of nano-structural deformation mechanisms. With further insights from molecular dynamics simulations, our study identified the critical steps in the synergistic deformation mechanisms responsible for the fracture resistance in CrCoNi.
||Characterization, Mechanical Properties, High-Entropy Alloys