利用扩展位错间的弹性作用能与层错能之间的平衡关系 ,对TiAl中〈1 0 1 ]和 1 / 2〈1 1 2 ]型超点阵位错在不同位向、不同分解组态下的分解宽度进行了理论计算 .结果表明 ,超点阵位错的分解宽度除了受层错能和位错性质 (刃或螺 )的影响外 ,还受弹性各向异性、超点阵位错类型及分解方式的影响 .在弹性各向异性的条件下 ,螺型 1 / 2〈1 1 2 ]超点阵位错的分解宽度比具有相同层错能的螺型〈1 0 1 ]超点阵位错的分解宽度大 ,而刃型 1 / 2〈1 1 2 ]超点阵位错的分解宽度则比〈1 0 1 ]超点阵位错的分解宽度小 .计算了弹性各向异性条件下超位错发生二分、三分、四分及发生共面和非共面分解时其分解宽度的变化情况 .这些结果为准确测定TiAl中的层错能和评估〈1 01 ]和 1 / 2〈1 1 2 ]型超点阵位错的可动性提供理论支持 Based on the equilibrium relationship between the elastic function of extended dislocations and the stacking fault energy, the dislocations of <1 0 1] and 1/2 <1 1 2] type superlattices in TiAl in different orientation and different decomposition groups The results show that the disintegration width of superlattice dislocations is affected by the anisotropy of elasticity, superlattice position Fault type and decomposition mode.Under the condition of elastic anisotropy, the dislocation width of the screw 1/2 <1 1 2] superlattice dislocation is smaller than that of the screw type <1 0 1] with the same stacking fault energy The disassembly width of dislocations is larger than that of dislocation dislocations of <1 0 1], and the dislocation width of dislocation of edge 1/2 <1 1 2] Under the condition of heterosexuality, the dislocation widths of superpositional dislocations occur when the coplanar and non-coplanar decomposition occurs. These results are accurate for the determination of the stacking fault energy and the evaluation in TiAl <1 01] and 1 / 2 <1 1 2] type superlattice dislocations provide theoretical support for the mobility