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 electro...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.展开更多
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)+11 种基金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 projectsupported by the Materials Simulation Center and the Institute for CyberSciencefunded by NSF through Grant OCI-0821527the XSEDE clusters supported by NSF through Grant ACI-1053575.
文摘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.
