In-situ study of initiation and extension of nano-thick defect-free channels in irradiated nickel  

作　　者：Shihao Li Ning Gao Weizhong Han 

机构地区：[1]Center for Advancing Materials Performance from the Nanoscale,State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an,710049,PR China [2]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou,450001,PR China [3]Institute of Frontier and Interdisciplinary Science and Key Laboratory of Particle Physics and Particle Irradiation,Shandong University,Qingdao,266237,PR China [4]Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou,730000,PR China

出　　处：《Journal of Materials Science & Technology》2020年第23期114-119,共6页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51922082,51971170,51942104 and11675230);the National Key Research and Development Program of China(2017YFB0702301);the 111 Project of China(Grant Number BP2018008)。

摘　　要：Radiation defects-induced plastic flow localization is the origin of loss of ductility in irradiated metals.Defect-free channels(DFCs)are a typical form of strain localization that lead to crack initiation and premature failure.A comprehensive understanding of the DFC dynamics is key to managing radiation boosted property degradation.Despite great research efforts,a clear mechanism of DFC remains unknown.Here,our in-situ tests on irradiated Ni pillars provide a real-time observation of the dynamics of DFCs,including DFC initiation,extension and thickening.The merging and spreading of dislocation loops serve as an alternative mechanism of dislocation sources that emit massive dislocations and initiate nano-thick DFCs inside the grain.Nano-thick DFCs were formed through chopping up or sweeping away of loops by mobile dislocations.Annihilation of opposite loops and interactions between loops and vacancies accelerate DFC extension.Activation of multiple dislocation sources and dislocation cross-slips are the mechanisms for DFC thickening.

关 键 词：Defect-free channel Dislocation loop IN-SITU Strain localization 

分 类 号：TB383.1[一般工业技术—材料科学与工程]