Atomic and electronic basis for the serrations of refractory high-entropy alloys  

作　　者：William Yi Wang Shun Li Shang Yi Wang Fengbo Han Kristopher A.Darling Yidong Wu Xie Xie Oleg N.Senkov Jinshan Li Xi Dong Hui Karin A.Dahmen Peter K.Liaw Laszlo J.Kecskes Zi-Kui Liu 

机构地区：[1]State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072 Shaanxi Province,China [2]Department of Materials Science and Engineering,The Pennsylvania State University,University Park,PA 16802,USA [3]U.S.Army Research Laboratory,Weapons and Materials Research Directorate,RDRL-WMM-B,Aberdeen Proving Ground,MD 21005,USA [4]State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China [5]Department of Materials Science and Engineering,The University of Tennessee,Knoxville,TN 37996,USA [6]Air Force Research Laboratory,Materials and Manufacturing Directorate,Wright-Patterson Air Force Base,OH 45433,USA [7]Department of Physics,University of Illinois at Urbana Champaign,Urbana,IL 61801,USA

出　　处：《npj Computational Materials》2017年第1期253-262,共10页计算材料学（英文）

基　　金：financially supported by the U.S.Army Research Laboratory(Project No.W911NF-08-2-0084);the United States National Science Foundation(Grant DMR-1006557);the National Natural Science Foundation of China(Grants 51690163,50871013,51271018,51271151,and 51571161);the support from the Fundamental Research Funds for the Central Universities in China(G2016KY0302);the Natural Science Basic Research Plan in Shaanxi province of China(2016JQ5003);supported through the Air Force on-site contract FA8650-10-5226 managed by UES,Inc.;the Department of Energy,Office of Fossil Energy,National Energy Technology Laboratory(DE-FE-0008855,DE-FE-0024054,and DE-FE-0011194);the U.S.Army Research Office project(W911NF-13-1-0438);the National Science Foundation(CMMI-1100080 and DMR-1611180);the Ministry of Science and Technology of Taiwan(MOST 105-2221-E-007-017-MY3);the support from the DE-FE-0011194 project;supported by the Materials Simulation Center and the Institute for CyberScience;funded by NSF through Grant OCI-0821527;the XSEDE clusters supported by NSF through Grant ACI-1053575.

摘　　要：Refractory high-entropy alloys present attractive mechanical properties,i.e.,high yield strength and fracture toughness,making them potential candidates for structural applications.Understandings of atomic and electronic interactions are important to reveal the origins for the formation of high-entropy alloys and their structure−dominated mechanical properties,thus enabling the development of a predictive approach for rapidly designing advanced materials.Here,we report the atomic and electronic basis for the valence−electron-concentration-categorized principles and the observed serration behavior in high-entropy alloys and highentropy metallic glass,including MoNbTaW,MoNbVW,MoTaVW,HfNbTiZr,and Vitreloy-1 MG(Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5)).We find that the yield strengths of high-entropy alloys and high-entropy metallic glass are a power-law function of the electron-work function,which is dominated by local atomic arrangements.Further,a reliance on the bonding-charge density provides a groundbreaking insight into the nature of loosely bonded spots in materials.The presence of strongly bonded clusters and weakly bonded glue atoms imply a serrated deformation of high-entropy alloys,resulting in intermittent avalanches of defects movement.

关 键 词：ALLOYS TOUGHNESS ENTROPY 

分 类 号：TG1[金属学及工艺—金属学]