Strengthening CoCrFeNi high-entropy alloy by Laves and boride phases

作     者：Xiu-gang Chen Gang Qin Xue-feng Gao Rui-run Chen Qiang Song Hong-zhi Cui Xiu-gang Chen;Gang Qin;Xue-feng Gao;Rui-run Chen;Qiang Song;Hong-zhi Cui

作者机构：School of Materials Science and EngineeringShandong University of Science and TechnologyQingdao 266500China School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China 

出 版 物：《China Foundry》 (中国铸造（英文版）)

年 卷 期：2022年第19卷第6期

页      面：457-463页

核心收录：

学科分类：08[工学] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the National Natural Science Foundation of China(No.51825401). 

主　　题：high-entropy alloy boride eutectic structure mechanical properties 

摘      要：To strengthen the face-centered-cubic(FCC)type CoCrFeNi high-entropy alloy(HEA)by in-situ reinforced phase,(CoCrFeNi)_(100-x)(NbB_(2))_(x)(x=0,2,4,6,8,at.%)alloys were prepared.Phase constitution,microstructure,tensile mechanical properties of the alloys were studied,and the mechanisms were discussed.Results show that the microstructure of all the reinforced alloys consists of the matrix FCC phase,Laves phase,and(Cr_(3)Fe)B_(x) phase.The eutectic structure and(Cr_(3)Fe)B_(x) phases are formed in the interdendritic region,and the eutectic structure is composed of Laves and FCC phases.When x increases from 0 to 8,i.e.,with increase of Nb and B elements,the volume fraction of Laves and(Cr_(3)Fe)B_(x) phases increases gradually from 0 to 5.84%and 8.3%,respectively.Tensile testing results show that the ultimate strength of the alloys increases gradually from 409 MPa to 658 MPa,while the fracture strain decreases from 75%to 1.6%.Fracture analysis shows that the crack originates from the(Cr_(3)Fe)B_(x) phase.The CoCrFeNi alloys are mainly strengthened by the second phase(Laves phase and boride phase).