【摘要】 γ—ＴｉＡｌ单晶中，＜０１１］超点阵位错的运动方向同晶体取向有关、当沿极射投影图００１一１１０—０１０单位三角形的００１－１１１－０２１区域中的取向变形时，ＳＩＳＦ偏位错为领先位错；而沿三角形中其余区域中的取向变形时，ＡＰＢ偏位错为领先位错．在反常温度区域中（即超点阵位错开动的温度范围内），前者的ＣＲＳＳ较高，形变的热激活焓也较高，＜０１１超点陈位错的脱钉过程更为困难，造成ＣＲＳＳ反常上升的速率较快．更多还原

【Abstract】 The direction of motion for <011] superlattice dislocations in ac-TiAl single crystalsdepends on the crystal orientation. SISF super-partials become leading partials when the orientation ofloading axis is in the 001-111-021 region of the 001 -110-010 unit triangle of the sterographic projection,while APB super--partials become the leading partials with loading axis orientation in the other regionof the unit triangle. Below the peak temperature of yield stress, the correspondent CRSS for superlatticeslip is relatively higher in the SISF case than in the APB case, the unlocking process of <011] superlatticedislocation is more difficult for the SISF case with higher thermal-activation enthalpy, thus resulting inthe increase of CRSS.更多还原