Atomistic dynamics of disconnection-mediated grain boundary plasticity:A case study of gold nanocrystals  

作　　者：Qi Zhu Haofei Zhou Yingbin Chen Guang Cao Chuang Deng Ze Zhang Jiangwei Wang 

机构地区：[1]Center of Electron Microscopy and State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China [2]Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials,Institute of Wenzhou,Zhejiang University,Wenzhou 325006,China [3]Center for X-Mechanics,Department of Engineering Mechanics,Zhejiang University,Hangzhou 310027,China [4]Department of Mechanical Engineering,University of Manitoba,Winnipeg,MB R3T 5V6,Canada

出　　处：《Journal of Materials Science & Technology》2022年第30期182-191,共10页材料科学技术（英文版）

基　　金：support of the National Key R&D Program of China(No.2021YFA1200201);the National Natural Science Foundation of China(Nos.52071284 and 51771172);support from NSERC Discovery grant(No.RGPIN-05834-2019)。

摘　　要：Grain boundary(GB)mediated deformation is a vital contributor to the plasticity of polycrystalline materials,where the disconnection model has become a widely recognized approach to depict the GB dynamics.However,experimental understanding of the atomistic disconnection dynamics remains scarce.In this case study of gold nanocrystals,atomistic disconnection dynamics governing the shear-coupled migration of flat GBs have been systematically investigated via in situ transmission electron microscopy nanomechanical testing supported by molecular dynamics simulations.Specifically,the site-dependent nucleation,shear-driven propagation,and diverse interactions associated with distinct GB disconnections are systematically elucidated and quantitatively compared.Moreover,the disconnection-mediated GB plasticity proves to prevail among different tilt and mixed GBs in gold.Eventually,a conceptual map of disconnection-mediated GB dynamics is established,which would furnish a unified understanding of GB plasticity in metallic materials.

关 键 词：Grain boundaries(GBs) Disconnection dynamics Plastic deformation In situ transmission electron microscopy(TEM) Metallic materials 

分 类 号：TG146.31[一般工业技术—材料科学与工程] TB383.1[金属学及工艺—金属材料]