Multistage strain-hardening behavior of ultrastrong and ductile lightweight refractory complex-concentrated alloys  

作　　者：Yuefei Jia Chang Ren Shiwei Wu Yongkun Mu Long Xu Yandong Jia Wentao Yan Jun Yi Gang Wang 

机构地区：[1]Institute of Materials,Shanghai University,Shanghai 200444,China [2]Zhejiang Institute of Advanced Materials,Shanghai University,Jiashan 314100,China [3]Department of Mechanical Engineering,National University of Singapore,117575,Singapore

出　　处：《Journal of Materials Science & Technology》2023年第18期73-87,共15页材料科学技术（英文版）

基　　金：supported by the open research fund of Songshan Lake Materials Laboratory(No.2021SLABFN06);the Innovation Pro-gram of Shanghai Municipal Education Commission(No.2021-01-07-00-09-E00114);the financial support from Program 173(No.2020-JCIQ-ZD-186-01);the Key Program of Science and Technology of Yun nan Province(No.202002AB080001-2);the National Natural Science Foundation of China(Nos.51971123,51925103);111 project(No.D16002);the financial support for the CSC scholarship(No.202006890046).

摘　　要：Lightweight high-entropy alloys or complex-concentrated alloys have demonstrated great potential for engineering applications due to their high strength and lightweight.However,a weak strain-hardening ability and a limited tensile ductility remain their major hindrance.Here,a multistage strain-hardening effect is developed to ensure a high strength and still a sufficient ductility in a rolled and annealed(Ti_(44)V_(28)Zr_(14)Nb_(14))_(98.5)Mo_(1.5)(at.%)lightweight refractory complex-concentrated alloy(M1.5A-LRCCA).This multistage strain-hardening behavior is related to the microstructure and the corresponding initial aver-age dislocation density and distribution by comparison with rolled and annealed Ti_(44)V_(28)Zr_(14)Nb_(14)(M0-LRCCA)and as-cast(Ti_(44)V_(28)Zr_(14)Nb_(14))_(98.5)Mo_(1.5)(M1.5C-LRCCA).The microstructure,with homogeneously distributed submicron precipitations,a moderate initial average dislocation density,and uniform disloca-tion distribution(e.g.,M1.5A-LRCCA),is susceptible to producing various deformation substructures,such as dislocation substructures(slip bands,Taylor lattices,microbands,DDWs),shear bands,and deformation twins,which results in the multistage strain-hardening behavior.This method of achieving multistage strain hardening behavior through a microstructure modulation is significant for engineering applications of lightweight high-entropy alloys or complex-concentrated alloys,and it might be extended to other lightweight and high-strength alloys.

关 键 词：High-entropy alloy/complex-contracted alloy LIGHTWEIGHT Strain hardening BCC Mechanical properties 

分 类 号：TG139[一般工业技术—材料科学与工程]