Entropy versus enthalpy in hexagonal-close-packed highentropy alloys  

作　　者：Xin-Wei Yang Xiao-Hui Shi Hui-Jun Yang Jun-Wei Qiao Peter KLiaw Yu-Cheng Wu 

机构地区：[1]College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan,030024,China [2]School of Materials Science and Engineering,University of Tennessee,Knoxville,37996,USA [3]School of Materials Science and Engineering,Hefei University of Technology,Hefei,230000,China

出　　处：《Rare Metals》2022年第8期2906-2920,共15页稀有金属（英文版）

基　　金：financially supported by the Natural Science Foundation of Shanxi Province,China (Nos. 201901D111105 and 201901D111114);the Key Research and Development Program of Shanxi Province (No.202102050201008);the National Science Foundation,United States (Nos.DMR-1611180 and 1809640);the U.S.Army Research Office (Nos.W911NF-131-0438 and W911NF-19-2-0049)

摘　　要：The addition of hexagonal-close-packed(hcp)non-rare-earth elements Zr,Ti and Co,to the 10-component hep rare-earth-based high-entropy alloys(HEAs)with a composition of ScYLaNdGdTbDyHoErLuX(X=Zr,Co and Ti)was investigated.The enthalpy of mixing between elements was found to have a significant effect on the formation of phases.The addition of Co combines with elements that had a strong chemical affinity to form intermetallic compounds by the effect of enthalpy.Ti was added with all elements with poor chemical affinity and exhibited rejection to form a phase alone.These were the two terminal manifestations of the role of enthalpy over entropy.Part of Zr was soluble in the matrix under the action of entropy,while the other part had a greater affinity for Sc than the other elements to form a precipitate under the action of enthalpy.This was the result of the local balance between the effect of enthalpy and entropy.The solid solution of the elements had different degrees of strengthening effect,among which Zr had the most excellent strengthening effect from 185 to 355 MPa,so the solid solution strengthening model and precipitation strengthening model were proposed to predict the strength of the alloy with the addition of Zr effectively.

关 键 词：High-entropy alloys Hexagonal close-packed(hcp) Phase formation rule Configuration entropy Mechanical properties 

分 类 号：TG139[一般工业技术—材料科学与工程]