Size-dependent mechanical properties and deformation mechanisms in Cu/NbMoTaW nanolaminates  

Cu/NbMoTaW纳米叠层材料具有尺寸效应的力学性能及变形机制（英文）

作　　者：Yufang Zhao Jinyu Zhang Yaqiang Wang Kai Wu Gang Liu Jun Sun 赵宇芳;张金钰;王亚强;吴凯;刘刚;孙军(State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University)

机构地区：[1]State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Science China Materials》2020年第3期444-452,共9页中国科学（材料科学（英文版）

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);the 111 Project 2.0 of China (BP2018008);the International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies;the 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)

摘　　要：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.高熵合金(HEA)由于其在恶劣环境中优异的力学性能引起了研究者的广泛关注.我们将高熵合金NbMoTaW引入到纳米叠层材料中,制备出等层厚的Cu/HEA纳米多层膜,综合研究了其具有尺寸效应的力学性能及变形行为.实验表明,Cu/HEA纳米多层膜的硬度随着层厚h的减小而增加,随后在h≤50 nm的区域到达一个平台,而应变速率敏感性出现了一个最大值,这是由于Cu和HEA两相对应变速率敏感性的影响从协同转变为竞争.在层厚较大时,非共格界面导致Cu/HEA多层膜在变形后出现了剪切带,并且软相Cu层主导变形.

关 键 词：high-entropy alloys nanolaminated structure INTERFACES strain rate sensitivity 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TG139[金属学及工艺—合金]