A novel cobalt-free oxide dispersion strengthened medium-entropy alloy with outstanding mechanical properties and irradiation resistance  

作　　者：Ao Fu Bin Liu Bo Liu Yuankui Cao Jian Wang Tao Liao Jia Li Qihong Fang Peter K.Liaw Yong Liu 

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [2]Key Laboratory of Radiation Physics and Technology of Ministry of Education,Institute of Nuclear Science and Technology,Sichuan University,Chengdu 610064,China [3]State Key Lab of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China [4]Department of Materials Science and Engineering,The University of Tennessee,Knoxville,TN 37996,USA

出　　处：《Journal of Materials Science & Technology》2023年第21期190-200,共11页材料科学技术（英文版）

基　　金：This work was supported by the National Natural Science Foun-dation of China(Nos.52020105013 and 52104365);the US National Science Foundation(Nos.DMR 1611180 and 1809640)with program directors,Drs.J.Yang,G.Shiflet,and D.Farkas.

摘　　要：A novel cobalt-free oxide dispersion strengthened(ODS)equiatomic FeCrNi medium entropy alloy(MEA)was successfully fabricated through mechanical alloying and hot extrusion(HE).The ODS FeCrNi MEA is composed of a single face-centered cubic(FCC)matrix,in which highly dispersed oxide nanoparticles,including Y_(2)Ti_(2)O_(7),Y_(2)TiO_(5) and Y_(2)O_(3),are uniformly distributed.Compared with the FeCrNi MEA,the ODS FeCrNi MEA exhibits the improved yield strength(1120 MPa)and ultimate tensile strength(1274 MPa)with adequate ductility retention(12.1%).Theoretical analysis of the strengthening mechanism indicates that the high strength is mainly attributed to the grain-boundary strengthening caused by fine grains and the precipitation strengthening resulted from the oxide nanoparticles.Meanwhile,the matrix that easily activates mechanical twinning during the deformation process is the main reason to ensure moderate ductility.In addition,the introduction of high-density oxide nanoparticles can disperse the defect distri-bution and suppress the defect growth and irradiation-induced segregation,leading to the excellent irra-diation resistance.These findings provide innovative guidance for the development of high-performance structural materials for future nuclear energy applications with balanced strength and ductility.

关 键 词：Medium-entropy alloys IRRADIATION Oxide nanoparticles Strength Deformation mechanism 

分 类 号：TG1[金属学及工艺—金属学]