Atomistic insights on the deformation mechanisms of amorphous/crystalline dual-phase high entropy alloys under nanoindentation

RC Han and HY Song and L Han and MR An, JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T, 25, 6027-6038 (2023).

DOI: 10.1016/j.jmrt.2023.07.066

The amorphous/crystalline (A/C) dual-phase nanostructured model is an effective method to improve the mechanical properties of high entropy alloys (HEAs). However, the defor-mation mechanism of the dual-phase HEAs during nanoindentation is still unclear. Here, the effect of the amorphous layer position and thickness on the deformation behavior and mechanical properties of the A/C dual-phase CoCrFeMnNi HEAs under nanoindentation is investigated by molecular dynamics simulation. The results show that the amorphous phase has a significant impact on the mechanical behavior of the HEAs, and the amor-phous layer plays a role in absorbing dislocations and hindering their continued move-ment. The embedding position of the amorphous layer has almost no effect on the elastic deformation of the HEAs. However, during the plastic deformation stage, as the insertion position of the amorphous layer in the HEAs moves downwards, the nanoindentation force of the HEAs shows an obvious increasing trend, which promotes deformation strength-ening. The results also indicate that the amorphous layer thickness affects its ability to absorb dislocations, and the dislocation lengths in the HEA with smaller amorphous phase thickness are significantly higher than those in the models with larger amorphous phase thickness.& COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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