Enhanced plasticity in refractory high-entropy alloy via multicomponent ceramic nanoparticle  

作　　者：Hongyi Li Fuhua Cao Tong Li Yuanyuan Tan Yan Chen Haiying Wang Peter K.Liaw Lanhong Dai 

机构地区：[1]State Key Laboratory of Nonlinear Mechanics,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Engineering Science,University of Chinese Academy of Sciences,Beijing 101408,China [3]Department of Materials Science and Engineering,The University of Tennessee,Knoxville,TN 37996-2100,USA

出　　处：《Journal of Materials Science & Technology》2024年第27期51-62,共12页材料科学技术(英文版)

基　　金：supported by the Ye Qisun Science Foun-dation of National Natural Science Foundation of China(No.U2141204);the NSFC(Nos.12102433 and 11972346);theNSFC Ba-sic Science Center Program for“Multiscale Problems in Nonlinear Mechanics”(No.11988102);the opening project of State Key Labo-ratory of Explosion Science and Technology(No.KFJJ23-03M);P.K.Liaw very much appreciates the support from the National Science Foundation(Nos.DMR-1611180,1809640,and 2226508)with pro-gram directors;Drs.J.Madison,J.Yang,G.Shiflet,and D.Farkas and the US Army Research Office(Nos.W911NF-13-1-0438 and W911NF-19-2-0049)with program managers,Drs.M.P.Bakas,S.N.Mathaudhu,and D.M.Stepp.

摘　　要：Refractory high-entropy alloys (RHEAs) exhibit remarkable strengths at elevated temperatures and are hence extremely promising candidates for high-temperature structural materials. However, the RHEAs with ordered superlattice structures generally suffer from poor room-temperature plasticity, which severely hampers their widespread applications. Here, we discovered that the introduction of multicomponent ceramic nanoparticles (MCNPs) into the RHEAs makes the problem alleviative and realizes a multifold increase in plasticity without sacrificing strength. The detailed characterizations show that the improvement originates from the chemical ordering-disordering transition near MCNPs in the B2-ordered RHEAs. This transition promotes the formation of local disordered regions where the mobility of dislocations is significantly enhanced. These regions wrap around MCNPs to form a unique heterogeneous structure, which suppresses the premature microcracks by the boosted dislocation mobility. Simultaneously, the existence of stable MCNPs prevents grain coarsening at elevated temperatures by Zener pinning. These novel alloy-design ideas shed new insights into developing RHEAs with an outstanding combination of strength and plasticity.

关 键 词：Refractory high-entropy superalloys PLASTICITY Multicomponent ceramic nanoparticles Ordering-disordering transition 

分 类 号：TG1[金属学及工艺—金属学]