Unexpected creep behavior in a rejuvenated metallic glass  

作　　者：J.P.Wu Y.Lin F.H.Duan Q.Chen H.T.Wang N.Li J.L.Wen J.Pan L.Liu 

机构地区：[1]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China [3]State Key Laboratory of Material Processing and Die&Mould Technology and School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [4]Laboratory of Nanomaterials&Nanomechanics,Department of Mechanical Engineering,City University of Hong Kong,Hong Kong,China [5]Wuhan National High Magnetic Field Center,Huazhong University of Science and Technology,Wuhan 430074,China [6]Shenzhen Polytechnic,Shenzhen 518055,China

出　　处：《Journal of Materials Science & Technology》2023年第32期140-149,共10页材料科学技术（英文版）

基　　金：the National Natural Science Foundation of China(Nos.52022100,51871217,52001075,and 51971097);J.P.is also grateful for support from the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2020194);Y.Lin thanks the China Postdoctoral Science Foundation(No.2021M701290).

摘　　要：Rejuvenation,bringing metallic glasses(MGs)to the younger and higher energy states,provides an alternative avenue to explore the interplay between the property and microstructures of MGs.In this study,the creep behavior of the Zr_(69.5)Cu_(12)Ni_(11)Al_(7.5)MGs was experimentally examined by controlling the energy state in terms of structural rejuvenation and thermal annealing.It is found that compared to the as-cast counterpart,the annealed MG at a lower energy state exhibits a higher hardness,a smaller displacement,and a lower creep rate due to the decreased free volume and the inhibited activation of the shear transformation zone.Conversely,the rejuvenated MG at a high energy state displays lower hardness and increased free volume content,yet it demonstrates superior creep resistance compared to its as-cast counterpart,which deviates from conventional understanding.This unexpected phenomenon occurs as the initial high-content free volume annihilates during creep,and strain hardening takes precedence over strain softening as the prevailing process during creep deformation,leading to a superior creep performance in extremely rejuvenated MGs.

关 键 词：Metallic glass Energy state REJUVENATION CREEP STRAIN-HARDENING 

分 类 号：TG139.8[一般工业技术—材料科学与工程]