In situ observation of the pseudoelasticity of twin boundary  

作　　者：Jingpeng Hou Keliang Qiu Fengshi Li Zhenyu Yang Yonghai Yue Yongjun Tian Zhongchang Wang Lin Guo 

机构地区：[1]School of Chemistry,Beijing Advanced Innovation Center for Biomedical Engineering,Beihang University,Beijing 100191,China [2]Institute of Solid Mechanics,School of Aeronautics Sciences and Engineering,Beihang University,Beijing 100191,China [3]Center for High Pressure Science,State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China [4]International Iberian Nanotechnology Laboratory(INL),Braga 4715-330,Portugal

出　　处：《Journal of Materials Science & Technology》2023年第35期200-207,共8页材料科学技术（英文版）

基　　金：Y.Y.is supported by the Natural Science Foundation of China(Nos.51922017 and 51972009).

摘　　要：Twin boundary(TB)is a special and fundamental internal interface that plays a key role in altering the mechanical and physical properties of materials.However,the atomistic deformation mechanism of TB re-mains under debate,of which the most concerned aspect is how TB would affect the mechanical strength and plasticity of a material.Herein,we introduce our new discovery that the pseudoelastic strain of a TB can recover with decomposition and escape of pile-up dislocations,demonstrated by imposing a sponta-neous pseudoelastic deformation with recoverable plastic bending strain up to 5.1%on a TB.We found that the steps on the curved TB gradually annihilated during the migration of the TB,which was in-duced by the slip of decomposition dislocations on the TB.The TB not only provides local strain harden-ing through interaction with dislocations during the loading stage but also acts as a channel for the fast movement of decomposition dislocations during the recovery stage.Beside,the TB can maintain excellent pseudoelasticity under a multicycle bending test,which may play an important role in improving the fa-tigue resistance of materials.These findings could open up a new avenue for optimizing the mechanical properties of materials by manipulating their twin boundaries at the nanoscale.

关 键 词：Twin boundary PSEUDOELASTICITY MIGRATION Dislocation-twin boundary interaction 

分 类 号：TB383.1[一般工业技术—材料科学与工程]