摘要
本文利用扫描透射电子显微术,从原子尺度研究Al-Cu-Mg合金中T相(Al20Cu2Mn3)晶体结构的特征。结果表明T相颗粒(010)面存在两种类型孪晶:层状滑移对称型和呈"蛛网"状向外辐射的多重对称型。对孪晶结构分析发现组成孪晶的"双瞳眼睛"状结构单元多数按规则的周期性平行排列,但也有少数区域以混乱的分布方式存在;在某些局部小区域,"双瞳眼睛"状结构单元转变成平行四边形单胞,从而造成晶体结构也发生相应的改变。
The high angle annular dark-field imaging technique in scanning transmission electron microscopy（HAADF-STEM） was used to investigate the microstructure features of the T-phase particles in a commercial Al-Cu-Mg alloy.The obtained images viewed along the T direction show that there are many microtwins in the T-phase particles.Two types of twinning microstructures exist in these particles： parallel microtwins and spiderweb-like multiple microtwins.It was observed that in the（010）T projection,a T-phase crystal consists of ＂eye-like＂ atomic structure units,and each unit has two heavy atomic columns in the core area surrounded by twelve other atomic columns.At the twin interfaces and the multiple twin junctions the arrangements of ＂eye-like＂ structure units are disordered.It is also shown that another different T-phase structure exists whose ＂eye-like＂ structure units are distorted significantly.
出处
《电子显微学报》
CAS
CSCD
2012年第4期301-307,共7页
Journal of Chinese Electron Microscopy Society
基金
国家重点基础研究发展计划(973)(No.2009CB623704)
国家自然科学基金资助项目(No.51171063)
