High entropy alloys(HEAs)have attracted extensive attention due to their excellent properties in harsh environments.Here,we introduced the HEA NbMoTaW into the laminated structure to synthesize the Cu/HEA nanolaminate...High entropy alloys(HEAs)have attracted extensive attention due to their excellent properties in harsh environments.Here,we introduced the HEA NbMoTaW into the laminated structure to synthesize the Cu/HEA nanolaminates(NLs)with equal layer thickness h spanning from 5 to 100 nm,and comparatively investigated the size dependent mechanical properties and plastic deformation.The experimental results demonstrated that the hardness of Cu/HEA NLs increased with decreasing h,and reached a plateau at h≤50 nm,while the strain rate sensitivity m unexpectedly went through a maximum with reducing h.The emergence of maximum m results from a transition from the synergetic effect of crystalline constituents to the competitive effect between crystalline Cu and amorphous-like NbMoTaW.Microstructural examinations revealed that shear banding caused by the incoherent Cu/HEA interfaces occurred under severe deformation,and the soft Cu layers dominated plastic deformation of Cu/HEA NLs with large h.展开更多
基金supported by the National Natural Science Foundation of China (51621063, 51722104, 51625103, 51790482, 51761135031 and 51571157)the National Key Research and Development Program of China (2017YFA0700701 and 2017YFB0702301)+6 种基金the 111 Project 2.0 of China (BP2018008)the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologiesthe Fundamental Research Funds for the Central Universities (xzy022019071)the Fok Ying-Tong Education Foundation (161096)China Postdoctoral Science Foundation (2017T100744)Shaanxi Province innovative talents promotion Projects (2018KJXX-004)the support from China Postdoctoral Science Foundation (2016M602811)
文摘High entropy alloys(HEAs)have attracted extensive attention due to their excellent properties in harsh environments.Here,we introduced the HEA NbMoTaW into the laminated structure to synthesize the Cu/HEA nanolaminates(NLs)with equal layer thickness h spanning from 5 to 100 nm,and comparatively investigated the size dependent mechanical properties and plastic deformation.The experimental results demonstrated that the hardness of Cu/HEA NLs increased with decreasing h,and reached a plateau at h≤50 nm,while the strain rate sensitivity m unexpectedly went through a maximum with reducing h.The emergence of maximum m results from a transition from the synergetic effect of crystalline constituents to the competitive effect between crystalline Cu and amorphous-like NbMoTaW.Microstructural examinations revealed that shear banding caused by the incoherent Cu/HEA interfaces occurred under severe deformation,and the soft Cu layers dominated plastic deformation of Cu/HEA NLs with large h.
