論文
ハイエントロピー合金における粒界からの転位放出現象: 粒界を構成する原子組成の不均質性の影響
2020 年 69 巻 2 号 p. 141-148
詳細
2020 年 69 巻 2 号 p. 141-148
High-Entropy Alloys (HEAs) are alloys in solid solution with five or more elements and exhibit excellent mechan-ical properties. However, the mechanism has not been fully understood yet. Because general grain boundaries (GBs) contain various size of atomic free volume, a deviation of atomic compositions at GBs may appear in HEAs by replacing atoms with different atomic sizes to reduce atomic free volume at GBs. In this study, the influence of the deviation of atomic compositions at GBs on dislocation emission from GBs in HEAs is investigated through two dimensional atomic simulations. Various equiatomic HEAs with five elements are modeled by a modified Morse (two body atomic) potential. Thermal equilibrium GBs at finite temperatures are obtained by hybrid Monte Carlo-molecular dynamics simulations. As results, GBs in HEAs mainly consist of two elements with the minimum and maximum atomic size and the critical stress to emit dislocations from the GBs increases as the deviation of atomic compositions becomes large.
