In order to investigate the characteristics of elliptical ultrasonic vibration cutting of TiC particle-reinforced titanium matrix composites, a two-dimensional thermodynamic coupled finite element cutting model was established based on the Johnson-Cook intrinsic structure model using ABAQUS simulation software, and the changes in cutting force, cutting temperature, machined surface shape, and particle fragmentation were obtained under the traditional cutting method and ultrasonic elliptical vibration cutting method. The results show that under the same process parameters, ultrasonic elliptical vibration cutting is better than conventional cutting in terms of surface profile; the stress direction tends to be horizontal during cutting and the TiC particles are mainly removed by cutting off. The average cutting force is significantly lower than conventional cutting, with a maximum reduction of 60%. The cutting temperature is also reduced, with a reduction of approximately 17.6%.

Processing TiCp/TC4 composites has always been difficult due to the mismatch between the mechanical and thermal properties of the matrix and the reinforced particles, which results in a variety of machined surface defects. To expose the mechanism of defect generated on the cutting surface of TiCp/TC4 composites and improve their cutting surface quality, a 3D finite element orthogonal turning simulation model of TiCp/TC4 composites is developed. The failure at the matrix-particle interface and the fracture and removal mechanism of the reinforcing phase particles are analyzed from a microscopic perspective using a single particle cutting simulation model. In addition, a three-dimensional cutting simulation model with randomly dispersed TiC particles and a volume fraction of 5% is developed, and various forms of cutting surface defects of TiCp/TC4 composites are examined. To verify the validity of the finite element simulation model, TiCp/TC4 composites with a volume fraction of 5% are selected for turning tests. For various cutting tools and particle relative positions, the simulation and test results show that the removal of particles takes the following forms: debonding, crushing, brittle fracture, and slight fracture at the top, leading to a shallow cavity, microcracks, residual TiC particles embedded in the cavity, and surface defects with severe plastic deformation of the matrix surrounding the cavity on the machined surface.