Study on the Influence of Velocity Effect for Elastic–Plastic Deformation of 3C-SiC Fractal Rough Surface Grinding

We have studied the influence of the velocity effect on the grinding of the 3C-SiC fractal rough surface. Based on the Weierstrass–Mandelbrot fractal surface and molecular dynamics method, the diamond grinding model of the 3C-SiC fractal rough surface has been established The grinding process has been simulated at three different speeds: 200 m/s, 400 m/s, and 600 m/s, and the structural changes of the workpiece during the grinding analyzed. Analysis of the velocity effect on the grinding of 3C-SiC fractal rough surfaces has been from various perspectives, including temperature, stress–strain, dislocations, and friction. In the ultra-high speed grinding range, as the grinding speed increases, the extrusion between the tool and the workpiece atoms increases, causing the atomic bonds to break more and the temperature to rise faster. Consequently, the workpiece becomes more susceptible to plastic deformation. At the same time, at high grinding speeds, with the increasing depth of grinding, the strain change fluctuation increases and the number of plastic deformations increases. At lower grinding speeds, as the grinding depth increases, the high strain zone decreases and the number of plastic deformations decreases. This has certain guiding significance for grinding and machining 3C-SiC with rough surfaces.