摘要
用金相法、XRD等技术研究了挤压态AZ31镁合金单向压缩过程中的退孪生行为,并探讨退孪生机理。结果表明,在应变量较低时,拉伸孪晶数量随变形量的增大而增多,而当应变量>4%时,随着变形量的增大,拉伸孪晶数量反而减少,即产生了退孪生现象。这种特殊的退孪生现象可以通过晶体转动理论解释,即随变形量的增大,基体逐渐转到硬取向,孪晶伴随转动,变形量较大时产生的{10 12}拉伸孪晶的受力状态随转动发生改变,在已孪生部分又发生一次{10 12}拉伸孪生,使原来已孪生部分取向再次与基体相同,即产生了退孪生。
Detwinning behavior of an extruded AZ31 magnesium alloy during compression deformation was investigated by means of metallography and X-ray diffraction （XRD） , and a detwinning mechanism was suggested. The results show that the fraction of twins increases with increasing strain when the strain is low, but decreases if the strain is higher than about 4%. It indicates that detwinning occurs in the process. The grain rotation theory can be used to explain this peculiar behavior. The rotation of matrix at higher strain results in the change of stress state of {10 12}tension twins activated at lower strain, and the twinned portions are capable of re-twinning, which causes the re-orientation of the twinned-portions.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第8期26-30,共5页
Transactions of Materials and Heat Treatment
基金
科技部国际合作项目(2011DFR50010)
关键词
镁合金
孪生
退孪生
压缩变形
magnesium alloy
twinning
detwinning
compressive deformation
