Coupling effects of stress and ion irradiation on the mechanical behaviors of copper nanowires  

作　　者：YANG ZhenYu JIAO FeiFe LU ZiXing WANG ZhiQiao 

机构地区：[1]School of Aeronautic Science and Engineering,BeiHang University [2]School of Engineering and Technology,China University of Geosciences

出　　处：《Science China Chemistry》2013年第3期498-505,共8页中国科学（化学英文版）

基　　金：supported by the National Natural Sciences Foundation of China (Grant Nos. 11002011,10902111 and 10932001);Fundamental Research Funds for the Central Universities

摘　　要：By using molecular dynamics simulations,we studied the ion irradiation induced damage in mechanically strained Cu nanowires and evaluated the effects of damage on the mechanical properties of nanowires.The stresses in the pre-strained nanowires can be released significantly by the dislocation emission from the cascade core when the strain is greater than 1%.In addition,comparison of the stress-strain relationships between the defect-free nanowire and the irradiated ones indicates that ion irradiation reduces the yield strength of the Cu nanowires,and both the yield stress and strain decrease with the increase of irradiation energy.The results are consistent with the microscopic mechanism of damage production by ion irradiation and provide quantitative information required for accessing the stability of nanomaterials subjected to mechanical loading and irradiation coupling effects.By using molecular dynamics simulations, we studied the ion irradiation induced damage in mechanically strained Cu nan- owires and evaluated the effects of damage on the mechanical properties of nanowires. The stresses in the pre-strained nan- owires can be released significantly by the dislocation emission from the cascade core when the strain is greater than 1%. In addition, comparison of the stress-strain relationships between the defect-free nanowire and the irradiated ones indicates that ion irradiation reduces the yield strength of the Cu nanowires, and both the yield stress and strain decrease with the increase of irradiation energy. The results are consistent with the microscopic mechanism of damage production by ion irradiation and provide quantitative information required for accessing the stability of nanomaterials subjected to mechanical loading and irra- diation coupling effects.

关 键 词：ion irradiation NANOWIRES molecular dynamics VACANCY DISLOCATION 

分 类 号：TG139.6[一般工业技术—材料科学与工程] TU447[金属学及工艺—合金]