Composition design study of strong and ductile Mo-alloyed CoCrNi medium-entropy alloys  

作　　者：J.X.Yan J.Y.Qin J.H.Liu H.Chen Y.H.Huang M.Liu C.H.Xia F.Wang X.D.Cui J.B.Yang Z.F.Zhang 

机构地区：[1]School of Materials Science and Engineering,Chongqing Jiaotong University,Chongqing 400074,China [2]Southwest Technology and Engineering Research Institute,Chongqing 400039,China [3]Institute of Chemical Materials,China Academy of Engineering Physics,Mianyang 621900,China [4]Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China

出　　处：《Journal of Materials Science & Technology》2024年第19期37-47,共11页材料科学技术（英文版）

基　　金：the funding support for the work by the National Natural Science Foundation of China(NSFC)under Grant No.52071316;the Youth Project of Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202300755);the Natural Science Foundation of Chongqing(Grant No.cstc2021jcyj-msxmX0697);the Project of Science Foundation in Chongqing Jiaotong University(Grant No.F1210023).

摘　　要：The assistance of alloying elements provides enormous opportunities for the discovery of high-performance face-centered cubic(FCC)medium-entropy alloys(MEAs).In this work,the influence of al-loying element Mo on the phase stability,stacking fault energy(SFE),deformation mechanisms,lattice distortion,and mechanical properties of(CoCrNi)100-x Mox(0≤x≤10)MEAs was synthetically explored with the first-principles calculations.It indicates that the FCC phase remains metastable at 0 K,and its stability degenerates with increasing Mo content.The monotonous decrease of SFE is revealed with the rise of Mo content,which promotes the activation of stacking faults,deformation twinning,or martensitic transformation.Raising Mo content also causes the aggravation of lattice distortion and thus triggers in-tense solid solution strengthening.Significantly,the essential criterion for the composition design of FCC(CoCrNi)100-x Mo MEAs with superior strength-ductility combination was established based on the syner-gistic effects between multiple deformation mechanisms and solid solution strengthening.According to the criterion,the optimal composition is predetermined as(CoCrNi)93 Mo7 MEA.The criterion is proved to be effective,and it can provide valuable inspiration for the development of alloying-element reinforced FCC multi-principal element alloys.

关 键 词：Medium-entropy alloys First-principles calculations Stacking-fault energy Solute strengthening Deformation twinning Mechanical properties 

分 类 号：TG14[一般工业技术—材料科学与工程]