Formation of coherent BCC/B2 microstructure and mechanical properties of Al-Ti-Zr-Nb-Ta-Cr/Mo light-weight refractory high-entropy alloys

作     者：Dong-Ming Jin Zhen-Hua Wang Jin-Feng Li Ben Niu Qing Wang Dong-Ming Jin;Zhen-Hua Wang;Jin-Feng Li;Ben Niu;Qing Wang

作者机构：Engineering Research Center of High Entropy Alloy Materials(Liaoning Province)Key Laboratory of Materials Modification by LaserIon and Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Institute of MaterialsChina Academy of Engineering PhysicsMianyang621908China 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2022年第41卷第8期

页      面：2886-2893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：financially supported by the National Natural Science Foundation of China (No.52171152) the Key Discipline and Major Project of Dalian Science and Technology Innovation Foundation (No.2020JJ25CY004) 

主　　题：High entropy alloys Coherent precipitation Microstructure Lattice misfit Precipitation strengthening 

摘      要：The present work investigated the formation of coherent body-centered-cubic(BCC)/B2 microstructure in Al-Ti-Zr-Nb-Ta-Cr/Mo refractory high-entropy alloy system,in which three alloys with the composition of Al_(2)Ti_(6) Zr_(2)Nb_(3)Ta_(2)(Cr/Mo)_(1)were designed.These as-cast alloy ingots were homogenized at 1573 K for 2 h and then aged at different temperatures for 24 h.It is found that the BCC/B2 coherent microstructure with cuboidal BCC nanoprecipitates into the B2 matrix would be formed in873 K-aged Al_(2)Ti_(6) Zr_(2)Nb_(3)Ta_(2)Cr_(0.5)Mo_(0.5)alloy with half Cr and half Mo,which is ascribed to a moderate lattice misfit(ε=0.94%)between BCC and B2 phases.It is due to the special coherent microstructure that results in a prominent mechanical property with the highest compressive yield strength(σ_(YS)=1314 MPa)and good plasticity among these alloys,while coarse Cr2 Ti and Zr_(5)Al_(3)particles are existed in 873 K-aged alloy with Cr1.After 1073 K aging,all these alloys with Cr_(1),Cr_(0.5)Mo_(0.5)and Mo_(1)consist of BCC,B2 and Zr_(5)Al_(3),in which BCC/B2 coherent microstructure is destabilized.The strengthening mechanism of BCC/B2 coherent microstructure in 873 K-aged alloy with Cr_(0.5)Mo_(0.5)was also discussed.