期刊
SCRIPTA MATERIALIA
卷 207, 期 -, 页码 -出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.scriptamat.2021.114278
关键词
Medium-entropy alloys; L1 (2) nanoparticles; Microstructure; Mechanical properties; Strengthening mechanisms
类别
资金
- Guangdong Provincial Department of Science and Technology [2017B090907015, 2018B090904004, 2017B030314048]
- Guangzhou Municipal Science and Technology Bureau [201907010010]
- Ministry of Science and Technology of the People's Republic of China [2020YFE0205300]
A novel high-entropy alloy with tailored microstructure exhibited excellent strength-ductility synergy and high working hardening rate. Contributions from grain boundary strengthening and precipitation strengthening to yield strength were estimated, and changes in microstructure were observed after tensile testing.
A novel f.c.c. (CoCrNi)(94)Al3Ti3 medium-entropy alloy strengthened with an L1(2) phase was designed using CALPHAD. Hot rolling, cold rolling, and heat treatment were used to produce a fine grain size (0.61 mu m) and a high volume fraction (0.37) of coherent 23.2 nm diameter L1(2) nanoparticles. This tailored microstructure exhibited an excellent strength-ductility synergy (yield stress similar to 1203 MPa, ultimate tensile strength similar to 1577 MPa, elongation similar to 24%) and a high working hardening rate (3700 MPa at strain of 5%). The contributions from grain boundary strengthening and precipitation strengthening to the yield strength were estimated to be similar to 61%. After the tensile tests, the fraction of LAGBs sharply increased and that of Sigma 3(n) coincidence site lattice boundaries decreased: inverse pole figures indicate the formation of a {101}< 111> texture. Such an ultrafine grain size suppressed deformation twinning, while applied stress led to a higher density of geometrically-necessary dislocations at the grain boundaries compared to the grain interiors. (C) 2021Acta Materialia Inc. Published by ElsevierLtd. 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