Significantly ameliorating room-temperature brittleness of refractory high-entropy alloys via in situ heterogeneous structure  

作　　者：Dong Han Baijun Yang Wenlong Xu Hongwang Yang Guofeng Han Xiaoming Wang Jianqiang Wang 

机构地区：[1]Shenyang National Laboratory for Materials Science,Institute of Metal Research,CAS,Shenyang 110016,China [2]School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China [3]National Key Lab for Remanufacturing,Beijing 100072,China

出　　处：《Journal of Materials Science & Technology》2024年第26期1-17,共17页材料科学技术(英文版)

基　　金：supported by the National Key Research&De-velopment Program of China(No.2022YFF0609002);the National Natural Science Foundation of China(Nos.U1908219,52171163,and 52271157);the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-2-2);the key Research&Devel-opment Plan of Jiangxi Province(No.20192ACB80001);the Natu-ral Science Foundation of Liaoning Province(No.2022-BS-001);the China Postdoctoral Science Foundation(No.2022M713210);the Shenyang National Laboratory for Materials Science.

摘　　要：Although refractory high-entropy alloys(RHEAs)possess excellent softening resistance and thermal sta-bility at high temperatures,their practical application is often limited due to room temperature(RT)brit-tleness.In this work,we successfully achieved RT plasticization in a brittle(TaMoTi)_(92)Al_(8)RHEA via in situ forming heterogeneous structure(HS)with the doping of Zr.Different from the mainstream design con-cept of“soft solid solution matrices with hard intermetallic phases”proposed in the literature,the newly developed TaMoZrTiAl RHEA is featured by a hard disordered BCC phase embedded into a soft intermetal-lic B2 matrix.Such an HS leads to the remarkable strength-plasticity synergy in this alloy at RT,showing a large plasticity of>20%,associated with a high strength of>2380 MPa.It was found that solid solu-tion strengthening and heterodeformation-induced strengthening caused by dislocation pile-ups at phase boundaries are responsible for the enhancement in the yield strength,while deformation-induced strain partition and the frequent operation of dislocation cross-slip substantially improve the work hardening capacity of alloy,thus enabling the high strength and good RT plasticity.In short,the current work not only reveals the micromechanisms of the influence of heterogeneous dual-phase structure on the RT me-chanical behaviour in RHEAs but also provides a useful strategy for plasticizing brittle RHEAs.

关 键 词：Refractory high-entropy alloy Heterogeneous structure Heterodeformation-induced hardening BRITTLENESS PLASTICITY B2 phase 

分 类 号：TG1[金属学及工艺—金属学]