Dynamic plastic evolution mechanism in cutting zone of nickel-based superalloy GH4169

Abstract

In the cutting process of GH4169 at high speed, the chips are mostly serrated. Serrated chips have an important impact on cutting force, surface integrity and tool wear. According to the microstructure of GH4169, the micro-deformation mechanism of GH4169 during cutting is studied. Through in-depth study of dislocation-stress-strain evolution mechanism, the influence of dislocation on work hardening and flow stress is analyzed from the microscopic viewpoint, and the relationship between shear angle and strain gradient is established. A constitutive model was established to characterize the effects of parameters such as strain rate, dislocation density, steady-state stress and cutting temperature on cutting deformation. The average relative error of the model was 4.26%. When cutting GH4169, the matrix phase mainly undergoes plastic deformation, and the reinforced phase mainly undergoes elastic deformation, and the reinforced phase is the main fracture source. The crack propagation of the reinforced phase will promote the further plastic deformation of the matrix phase. By studying the interaction between two phases in cutting, the generated process of sawtooth chip was revealed, and the mechanism of cutting deformation was explained from the microscopic view.