文献类型：期刊文献

英文题名：Chemical short-range order strengthening mechanism in CoCrNi medium-entropy alloy under nanoindentation

作者：Yang, Xiaofeng[1];Xi, Yongzhi[1];He, Chenyun[1];Chen, Hao[1];Zhang, Xiancheng[1];Tu, ShanTung[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China

年份：2022

卷号：209

外文期刊名：SCRIPTA MATERIALIA

收录：;EI(收录号：20214511110076);WOS:【SCI-EXPANDED(收录号:WOS:000721513100001)】；

基金：This work was supported financially by the National Natural Science Foundation of China (Nos. 52005186 and 51725503) and 111 Project. HC acknowledges supports by Shanghai Sailing Program (20YF1409400). And Zhang XC is also grateful for the Innovation Program of Shanghai Municipal Education Commission (201901-07-00-02-E00 068).

语种：英文

外文关键词：Medium-entropy alloys; Chemical short-range order; Strengthening mechanism; Nanoindentation; Molecular dynamics

摘要：The strengthening effect of chemical short-range order (SRO) structure in CoCrNi medium-entropy alloy (MEA) was investigated using molecular dynamics (MD) simulations of nanoindentation. The quantitative correlation between SRO parameters and mechanical properties was established. Results show that the strength and hardness of CoCrNi MEA increase with increasing chemical SRO parameters and reach a stable value with steady SRO structure. Compared with random solid solution (RSS) state model, the average hardness increases 8 . 1% in an intermediate SRO model and 13 . 7% in a stable SRO model. The dislocation nucleation force of SRO model is 55% larger than RSS model. Moreover, dislocation pinning induced by local Ni SRO structure, as well as the promoted unique dislocation interaction were observed during the nanoindentation process. Finally, results also show that as the temperature rises, the enhancement of hardness becomes more significant ( 11 . 4% at 70 K, 17 . 24% at 300 K, and 23 . 8% at 800 K). (c) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.