原子分辨的材料力学行为实验系统与晶界塑性原子机制  

In situ atomic⁃resolution mechanical equipment and atomistic mechanisms of grain boundary plasticity

作　　者：韩晓东[1] 王立华[1] 张泽[2] HAN Xiao-dong;WANG Li-hua;ZHANG Ze(Beijing Key Laboratory of Microstructure and Advanced Materials,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124;Center of Electron Microscopy,State Key Laboratory of Silicon and Advanced Semiconductor Materials,School of Material Science and Engineering,Zhejiang University,Hangzhou Zhejiang 310027,China)

机构地区：[1]北京工业大学固体微结构与性能北京市重点实验室,材料与制造学部,北京100124 [2]浙江大学电子显微镜中心,硅及先进半导体材料全国重点实验室,材料科学与工程学院,浙江杭州310027

出　　处：《电子显微学报》2023年第4期543-564,共22页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.52201145).

摘　　要：原子分辨的材料力学性能实验方法具有原子分辨功能,可实现外力作用下材料的组织结构与缺陷相互作用,以及微观结构在时间-空间演化过程的观测。受制约于高空间分辨电子光学系统的要求,透射电子显微镜的物镜极靴空间极小,原子分辨的原位力学实验系统在国际领域长期没有突破,基本属于空白。本文综述了研究小组近二十年来围绕原子分辨材料力学行为的研究工作,包括研发原子分辨的材料力学行为实验系统,在实验系统基础上发展的实验方法及开展的相关科学研究。科学研究主要在多晶金属中的晶界塑性原子机制方面取得的较系统的工作,包括发现晶粒转动位错攀移机制、晶界滑移机制、晶界位错攀移与阶错(disconnection)反应机制、晶界位错锁形核与解锁机制、晶界迁移与扩散机制、晶界发射偏位错形核孪晶机制、孪晶界位错塞积与位错交滑移机制等。上述实验系统和相关科学仪器研发上取得的进展为原子尺度动态观测材料弹塑性力学行为和界面弹塑性机制的研究提供了方法学基础。晶界塑性原子机制的科学发现有助于发展先进结构材料体系。The atomic⁃scale resolution mechanical device enables observation of the interaction process of defects,as well as the time⁃resolved evolution process of microstructures during the deformation.Due to the stringent requirements of the electron optical system of high spatial resolution transmission electron microscopes(TEM),the pole piece of TEM with very limited space,this make the in⁃situ mechanical experiments with atomic resolution capabilities is lacking.This paper reviews the progress of our group in the field of atomic⁃scale deformation mechanism of metallic materials over the past two decades.This includes the development of atomic⁃resolution deformation equipment,experimental method,and related scientific discoveries.The scientific research mainly focuses on the atomic mechanisms of plasticity at grain boundary(GB)in polycrystalline metals.The discoveries include:grain rotation via GB dislocation climb,grain boundary slip mechanisms,grain boundary dislocation climb and interact with disconnection,GB dislocation lock generation and destruction,GB migration and diffusion mechanisms,dislocation nucleated from GB lead to twin nucleation,and dislocation pile⁃up and dislocation cross⁃slip at twin boundaries.The progress experimental systems and related scientific instruments mentioned above provides a method ological foundation for studying the inter⁃grained and intra⁃grained deformation mechanisms of materials at the atomic scale.The scientific discoveries regarding GB plasticity provide important guidance for development of advanced structural materials.

关 键 词：原位原子尺度 透射电子显微镜 位错 晶界 变形机制 

分 类 号：TG115.215.3[金属学及工艺—物理冶金] O76[金属学及工艺—金属学] O77[理学—晶体学] O482[一般工业技术—材料科学与工程] TB34