通过TEM原位拉伸试验对双相TiAl基合金γ相中各类变形系统的可动性进行了研究。结果表明,双相TiAl基合金γ相中的(1/2)<110]普通位错具有良好的可动性,<011]和(1/2)<112]超点阵位错滑移系很难开动,其临界分切应力至少比普通位错的分别大3.8和4.2倍以上。γ相容易发生形变孪生,且形变孪晶在反向应力作用下易于恢复,但通常情况下孪生切变只能是单向的。 The in-situ tensile test of TEM was used to study the mobility of various deformation systems in the γ-phase of TiAl-based alloys. The results show that the (1/2) <110] common dislocations in the γ phase of the dual-phase TiAl-based alloys have good mobility, <011] and (1/2) <112] superlattice dislocation slip systems It is difficult to start, the critical shear stress at least 3.8 and 4.2 times larger than ordinary dislocation. γ phase prone to deformation twin, and the deformation of twins in the reverse stress easily restored, but usually the twin shear can only be one-way.