期刊
ACTA MATERIALIA
卷 143, 期 -, 页码 257-264出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2017.10.014
关键词
High-entropy alloys; CoCrFeMnNi plastic deformation mechanisms; Stress relaxation; Dislocations; Activation volume
资金
- German Research Foundation (Deutsche Forschungsgemeinschaft DFG) [LA 3607/1-1]
- DFG
- European Research Council Advanced Grant, Predictive Computational Metallurgy, ERC [339081 - PreCoMet]
- U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division
To reveal the operating mechanisms of plastic deformation in an FCC high-entropy alloy, the activation volumes in CrMnFeCoNi have been measured as a function of plastic strain and temperature between 77 K and 423 K using repeated load relaxation experiments. At the yield stress, sigma(y), the activation volume varies from similar to 60 b(3) at 77 K to similar to 360 b(3) at 293 K and scales inversely with yield stress. With increasing plastic strain, the activation volume decreases and the trends follow the Cottrell-Stokes law, according to which the inverse activation volume should increase linearly with sigma - sigma(y) (Haasen plot). This is consistent with the notion that hardening due to an increase in the density of forest dislocations is naturally associated with a decrease in the activation volume because the spacing between dislocations decreases. The values and trends in activation volume agree with theoretical predictions that treat the HEA as a high-concentration solid-solution-strengthened alloy. These results demonstrate that this HEA deforms by the mechanisms typical of solute strengthening in FCC alloys, and thus indicate that the high compositional/structural complexity does not introduce any new intrinsic deformation mechanisms. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据