应变对面心立方结构孪晶纳米线变形机制影响的原位原子尺度研究  

Effect of strain on the deformation mechanism of twin-structured Ni nanowires(NWs)

作　　者：杨成鹏 孙涛 韦如建 卢艳[1] 孔德利[1] 罗俊峰 贺昕 熊晓东 王兴权 王立华[1] 张泽[1,3] 韩晓东[1] YANG Cheng-peng;SUN Tao;WEI Ru-jian;LU Yan;KONG De-li;LUO Jun-feng;HE Xin;XIONG Xiao-dong;WANG Xing-quan;WANG Li-hua;ZHANG Ze;HAN Xiao-dong(Beijing Key Lab of Microstructure and Property of Advanced Material,Institute of Microstructure and Properties of Advanced Materials,Beijing University of Technology,Beijing 100124;Grikin Advanced Materials CO.LTD.,Beijing 102200;Department of Materials Science,Zhejiang University,Hangzhou Zhangjiang 310007,China)

机构地区：[1]北京工业大学固体微结构与性能研究所,北京市先进材料微结构与性能重点实验室,北京100124 [2]有研亿金新材料有限公司,北京102200 [3]浙江大学材料科学与工程学院,浙江杭州310007

出　　处：《电子显微学报》2020年第5期476-486,共11页Journal of Chinese Electron Microscopy Society

基　　金：国家重点研发项目(No.2017YFB0305501);国家自然科学基金资助项目(Nos.11722429,51771104,11374030,11327901);国家自然科学基金重点项目(No.11234011);中国霍英东教育基金资助项目(No.151006)。

摘　　要：本文利用原位实验技术,在透射电镜中实现了对直径约为40 nm的孪晶结构Ni纳米线(D=~40 nm)的弯曲变形实验,并对其塑性变形机制进行了原位原子尺度研究。原位原子尺度研究表明,弯曲应变对孪晶结构Ni纳米线的塑性行为有显著影响。在弯曲变形的初始阶段,塑性变形受位错行为控制,并且孪晶厚度对位错类型和滑移系具有重要影响。随着弯曲应变的增加,纳米线中观察到了连续的晶格畸变以及面心立方-体心四方的相转变。当弯曲应变继续增加超过~30%时,塑性变形方式由晶格畸变/塌陷引起的晶界形核主导。本实验提供了孪晶结构Ni纳米线在大塑性变形下的塑性变形图像,对理解不同的弯曲应变对孪晶结构Ni纳米线变形机制的影响具有借鉴意义。Using home-made techniques,the in situ atomic-scale bending experiments were conducted on twin-structural Ni nanowires(NWs)(D=~40 nm).A number of in situ atomic-scale observations indicated that the plastic activities of twin-structural Ni NWs can be significantly affected by the bending strain.In the early stages of bending,their plastic deformations were controlled by dislocation activities,and there was a strong effect of twin thickness on dislocation type and glide systems.With bending strain increasing,fcc-bct phase transition was observed.When the bending strain increased to a significant level,the grain boundaries(GBs)that resulted from dislocation activities and lattice distortion/collapse were detected.This study provided a plastic deformation picture of the twin-structured Ni NWs after severe plastic deformation,and advanced our understanding of how the bending strain affected the deformation mechanisms of twin-structural Ni.

关 键 词：面心立方金属 孪晶结构镍纳米线 塑性机制 相变 

分 类 号：O733[理学—晶体学] TG383[金属学及工艺—金属压力加工]