Compression Deformation Mechanisms at the Nanoscale in Magnesium Single Crystal
来源期刊：Acta Metallurgica Sinica2013年第1期
论文作者：Yafang GUO Xiaozhi TANG Yuesheng WANG Zhengdao WANG Sidney YIP
文章页码：75 - 84
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 <a+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 {102} and {101} twins can be activated under c-axis tension, while compression twins will not occur when the c/a 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.
Yafang GUO1，Xiaozhi TANG1，Yuesheng WANG1，Zhengdao WANG1，Sidney YIP2
1. Institute of Engineering Mechanics, Beijing Jiaotong University2. Department of Nuclear Science and Engineering, Massachusetts Institute of Technology
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 <a+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 {102} and {101} twins can be activated under c-axis tension, while compression twins will not occur when the c/a 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：
