Compression Deformation Mechanisms at the Nanoscale in Magnesium Single Crystal  

作　　者：Yafang GUO Xiaozhi TANG Yuesheng WANG Zhengdao WANG Sidney YIP 

机构地区：[1]Institute of Engineering Mechanics, Beijing Jiaotong University [2]Department of Nuclear Science and Engineering, Massachusetts Institute of Technology

出　　处：《Acta Metallurgica Sinica(English Letters)》2013年第1期75-84,共10页金属学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 11072026 and 10632020);the Fundamental Research Funds for the Central Universities (No. 2009JBZ015)

摘　　要：The dominant deformation mode at low temperatures for magnesium and its alloys is generally regarded to be twinning because of the hcp crystal structure. More recently, the phenomenon of a ＂loss＂ of the twins has been reported in microcompression experiments of the magnesium single crystals. Molecular dynamics simulation of compression deformation shows that the pyramidal 〈α ＋ c〉 slip dominates compression behavior at the nanoscale. No compression twins are observed at different temperatures at different loadings and boundary conditions. This is explained by the analyses, that is, the {10^_12} and {10^11} twins can be activated under c-axis tension, while compression twins will not occur when the c/α ratio of the hcp metal is below √3. Our theoretical and simulation results are consistent with recent microcompression experiments of the magnesium （0001） single crystals.The dominant deformation mode at low temperatures for magnesium and its alloys is generally regarded to be twinning because of the hcp crystal structure. More recently, the phenomenon of a ＂loss＂ of the twins has been reported in microcompression experiments of the magnesium single crystals. Molecular dynamics simulation of compression deformation shows that the pyramidal 〈α ＋ c〉 slip dominates compression behavior at the nanoscale. No compression twins are observed at different temperatures at different loadings and boundary conditions. This is explained by the analyses, that is, the {10^_12} and {10^11} twins can be activated under c-axis tension, while compression twins will not occur when the c/α ratio of the hcp metal is below √3. Our theoretical and simulation results are consistent with recent microcompression experiments of the magnesium （0001） single crystals.

关 键 词：MAGNESIUM Compression SLIP Molecular dynamics simulation 

分 类 号：TG146.22[一般工业技术—材料科学与工程]