Stacking Fault Driven Phase Transformation in CrCoNi Medium Entropy Alloy

• DOI: 10.1021/acs.nanolett.0c04244
• Publication Date: 2021-01-19T15:23:26Z
• Authors: Haiyan He; Muhammad Naeem; Fan Zhang; Yilu Zhao; Stefanus Harjo; Takuro Kawasaki; Bing Wang; Xuelian Wu; Si Lan; Zhenduo Wu; Wen Yin; Yuan Wu; Zhaoping Lu; Ji-Jung Kai; Chain-Tsuan Liu; Xun-Li Wang
• Keywords: Stacking fault; High-Entropy Alloys; Ductility (Earth science)

Phase transformation is an effective means to increase the ductility of a material. However, even for commonly observed face-centered-cubic hexagonal-close-packed (fcc-to-hcp) phase transformation, underlying mechanisms are far from being settled. In fact, different pathways have been proposed, especially with regard nucleation hcp at nanoscale. CrCoNi, so-called medium-entropy alloy, fcc-to-hcp has long anticipated. Here, we report in situ loading study neutron diffraction, which revealed bulk CrCoNi 15 K under tensile loading. By correlating deformation characteristics fcc development phase, it shown that was triggered by intrinsic stacking faults. The confirmation adds myriads available together underpin unusually large low temperatures.