γ-TiAl合金部件需要磨削加工以保证其装配精度，而低塑性金属间化合物γ-TiAl合金的力学性能对磨削表面完整性极为敏感。本工作研究了磨削深度对γ-TiAl合金样品表面形貌、表层显微组织、显微硬度等表面完整性参数及最终疲劳性能的影响。结果表明，0.5 mm及以上深度磨削样品表面易产生裂纹，而0.2 mm及以下深度磨削样品表面完好，这与磨削变形热温升导致的冷却收缩拉应力过大有关。随着磨削深度增大，粗糙度参数的轮廓算术平均偏差(R_a)和微观不平度的十点平均高度(R_z)增大，偏度(R_sk)减小。表层γ + α₂片层沿磨削方向弯曲变形，相应变形层厚度随着磨削量增大而增大，而显微硬度由表及里先减小后增大。γ-TiAl合金650℃加载440 MPa旋转弯曲疲劳寿命随着磨削深度增大而减小，磨削深度0.05 mm的样品疲劳寿命大于10⁶ cyc，磨削深度0.2 mm的样品疲劳寿命约为10⁴ cyc，其断口裂纹源可观察到磨削痕迹，这与其表面沟槽应力集中有关。γ-TiAl合金疲劳寿命随着R_z的增大而减小，2者呈非线性关系；当R_z小于4 μm时，疲劳寿命稳定在10⁶ cyc以上。

γ-TiAl is a family of promising structural materials with low density, high stiffness, and good oxidation and creep resistances at elevated temperatures. They can replace heavier nickel-based alloys at 600-800^oC; thus, they are used in the construction of low-pressure turbine blades for aeroengines, i.e., General Electric next-generation and leading edge aviation propulsion. Grinding is an important processing step in blade production to ensure the accuracy of assembling. However, the limited ductility and fracture toughness at room temperature and low thermal conductivity of γ-TiAl alloys narrow the parameter windows of the grinding process. Cracks often form on the surface when the processing parameters are not well controlled. Additionally, grinding greatly influences the surface integrity (i.e., roughness, microstructure, and hardness), which influences the mechanical properties, especially those of brittle γ-TiAl alloys that are sensitive to notch. Grinding depth is a major parameter in blade production because it influences quality and efficiency. Investigating the effect of grinding depth on the surface integrity and fatigue properties of γ-TiAl samples is necessary to optimize the grinding process and identify the major factors of surface integrity that guarantee optimal mechanical properties. In this work, cast γ-TiAl alloy (Ti-45Al-2Nb-2Mn-1B, atomic fraction, %) samples were ground with different depths. The surface integrity (surface roughness, microstructure, and microhardness) and fatigue properties of the samples were compared. Cracks were detected in samples ground to 0.5 and 1 mm depths, while no cracks were detected in samples ground to 0.2 mm or less depths, this is related to the tensile stress induced by temperature increase caused by deformation heat. With the increased grinding depth, the number and depth of grooves increased and for the surface roughness parameters, arithmetic mean deviation and 10-point mean roughness (R_z) increased, while skewness decreased. The γ + α₂ lamellae bended in the surface layer and layer thickness increased with the increased grinding depth. The microhardness initially decreased and then increased from the surface to the interior. The rotating bending fatigue life at 650^oC under a load of 440 MPa decreased with the increased grinding depth: it was > 10⁶ cyc at 0.05 mm grinding depth but dropped to ~10⁴ cyc at 0.2 mm grinding depth. Fracture surface analysis showed that the cracks mainly nucleated at the surface grooves caused by grinding, which resulted in stress concentration and reduced the fatigue life of samples ground to 0.2 mm depth. The fatigue life decreased with increasing R_z, but remained above 10⁶ cyc when R_z was less than 4 μm. A nonlinear relationship between fatigue life and R_z was shown.