图1. L1₀结构TiAl (111)面滑移/孪晶变形模式示意图

Fig.1. Schematic for the slip/twinning systems on (111) plane of L1₀-TiAl, together with Burgers vectors for superlattice dislocation (SD, [10$\bar{1}$], [$\bar{1}$01] and $\frac{1}{2}$[11$\bar{2}$], named SD_I, SD_II and $\frac{1}{2}$[11$\bar{2}$] SD), ordinary dislocation (OD, $\frac{1}{2}$[1$\bar{1}$0]) and twinning (TW, $\frac{1}{6}$[11$\bar{2}$]) and the lowest energy full-dissociation paths. The different sizes of circles for atoms (red for Ti and blue for Al) stand for three consecutive (111) layers, marked by A, B and C. The red and blue backgrounds correspond to the superlattice intrinsic stacking fault (SISF) and complex stacking fault (CSF) leading paths, respectively. τ is the projection of external stress on the (111) plane (gray arrow). θ is the angle measured from [11$\bar{2}$] direction to τ. APB stands for the antiphase boundary