Compression Deformation Mechanisms at the Nanoscale in Magnesium Single Crystal

• 作 者: Yafang GUO Xiaozhi TANG Yuesheng WANG Zhengdao WANG Sidney YIP
• 机 构: Institute of Engineering Mechanics, Beijing Jiaotong University,Department of Nuclear Science and En
• 出 处: Acta Metallurgica Sinica(English Letters)
• 发表日期: 2013年01期
• 关键词: magnesium twins plasticity Compression tensile bands pyramidal explained accommo

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 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2} and {101} 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. The dominant deformation mode at low temperatures for magnesium and its alloys is generally considered to be twinning because of 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 that that the pyramidal 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 analyzes, that is, the {102} and {101} 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.