摘要
采用同步辐射X射线原位成像与衍射技术研究了不同孪晶含量的Mg-3Al-1Zn合金在单轴压缩下的变形行为。实验选取原始镁合金及其经应变4.3%和9.4%预压缩得到的具有不同孪晶含量的预制孪晶镁合金作为研究对象,在相同的实验条件下开展单轴压缩实验,加载过程中同时得到宏观尺度应力-应变曲线、细观尺度变形图像和微观尺度X射线衍射图谱。分别对X射线成像图像和X射线衍射图谱进行数字图像相关和积分处理,获得变形场和孪晶变形特征。结果表明,单轴压缩加载下原始镁合金中形成大量的{101^(-)2}孪晶,而预制孪晶镁合金样品产生了大量的{101^(-)2}-{101^(-)2}双孪晶,{101^(-)2}孪晶和{101^(-)2}-{101^(-)2}双孪晶均可以通过减缓应变集中过程促使应变硬化率增加。相较于4.3%预压缩试样,9.4%预压缩试样中形成的{101^(-)2}-{101^(-)2}双孪晶更多,减缓应变集中的效率更高,使得塑性变形过程中应变硬化率及其增幅均处于较高水平。
In situ synchrotron radiation X-ray imaging and diffraction are employed to investigate the deformation behavior of Mg-3Al-1Zn alloy with different twin contents under uniaxial compression.The asreceived magnesium alloy is compressed by 4.3%and 9.4%strain to fabricate twins with different contents,the pre-compressed and as-received magnesium alloys are subjected to uniaxial compression under the same condition,and the macroscale stress-strain curves,mesoscale deformation imaging sequence,and microscale X-ray diffraction patterns are obtained simultaneously.The imaging sequences are analyzed via digital image correlation method to resolve deformation fields,and the X-ray diffraction patterns are integrated to identify deformation twins.The results show that abundant{101^(-)2}and{101^(-)2}-{101^(-)2}twins are activated in the as-received and pre-twined magnesium alloy during uniaxial compression,respectively.Both{101^(-)2}and{101^(-)2}-{101^(-)2}twins can boost the strain hardening rate by slowing the strain localization process.Compared with the 4.3%pre-compressed sample,more{101^(-)2}-{101^(-)2}twins are formed in the 9.4%pre-compressed sample,leading to higher efficiency in slowing down strain localization,so that the strain hardening rate and its increase rate are at a high value during uniaxial compression.
作者
王叶
卢磊
WANG Ye;LU Lei(School of Physical Science and Technology,Southwest Jiaotong University,Chengdu 610031,China;School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《材料工程》
北大核心
2026年第1期187-192,共6页
Journal of Materials Engineering
