Surface Microstructure Characteristics of Form Grinding Tenon Teeth of Anisotropic DZ125 Nickel-based Superalloy Turbine Blades

To reveal the surface quality and microstructure evolution mechanism during form grinding of turbine tenon teeth of DZ125 nickel‑based superalloy, an experimental investigation was conducted on creep feed deep grinding of anisotropic DZ125 blade tenon teeth. Using electroplated diamond grinding wheels, the microstructure evolution of the grinding surface under different grinding parameters was studied. Quantitative characterization was performed on the microstructure, elemental distribution, grain boundary characteristics, and dislocation density at the tooth roots and tooth tips of the tenon teeth. The results show that no phase transformation of the γ matrix phase and γ' strengthening phase occurred during grinding, and no significant segregation of elements such as Al, Mo, and Cr was detected. However, the microstructure exhibited obvious plastic deformation. The plastic deformation layer depth at the tooth root was approximately 85 μm, characterized by significant grain refinement, an increased proportion of low‑angle grain boundaries, and a higher geometric dislocation density. In contrast, the deformation degree at the tooth tip was relatively mild. The difference in dislocation density distribution indicates that the residual compressive stress at the tooth root is higher than that at the tooth tip, and there is a strong correlation between microstructure evolution and residual stress formation. This study reveals the evolution law of surface integrity during form grinding of turbine tenon teeth at the microscale, providing a theoretical basis for optimizing the precision grinding process of aero‑engine turbine blade tenon teeth.