The Evolution of Defects in Deformed Cu-Ni-Si Alloys during Isochronal Annealing Studied by Positron Annihilation  

作　　者：QI Ning JIA Yan-Lin LIU Hui-Qun YI Dan-Qing CHEN Zhi-Quan 祁宁;贾延琳;刘会群;易丹青;陈志权(Hubei Nuclear Solid Physics Key Laboratory,Department of Physics,Wuhan University,Wuhan 430072;School of Materials Science and Engineering,Central South University,Changsha 410083)

机构地区：[1]Hubei Nuclear Solid Physics Key Laboratory,Department of Physics,Wuhan University,Wuhan 430072 [2]School of Materials Science and Engineering,Central South University,Changsha 410083

出　　处：《Chinese Physics Letters》2012年第12期219-222,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 11075120,51071177;the Fund for Fostering Talents in Basic Science of the National Natural Science Foundation of China under Grant No J0830310.

摘　　要：The effect of isochronal annealing on the deformation-induced defects in pure Cu and Cu-Ni-Si alloys is studied by positron annihilation spectroscopy.For the cold-rolled Cu,annealing up to 900℃ causes a gradual recovery of the deformation-induced defects and monotonous decrease of the hardness.This indicates that its hardening is mainly related with defects such as dislocations.However,for the hot-rolled and quenched Cu-Ni-Si alloy,although there is a partial recovery of defects after annealing below 500℃,formation of additional defects is observed after annealing above 500℃.The hardness of Cu-Ni-Si alloy has a maximum value after annealing at 500℃,which suggests that the hardening of Cu-Ni-Si alloy is not due to defects,but primarily due to the precipitation formed during annealing.Further annealing of the Cu-Ni-Si alloy above 500℃ results in over-aging effect and the precipitates lose coherence with the host matrix,which leads to positron trapping by vacancy clusters in the incoherent interface region.

关 键 词：ALLOY ANNEALING POSITRON 

分 类 号：TG1[金属学及工艺—金属学]