Effects of ultrasonic vibration-assisted machining methods on the surface polishing of silicon carbide

The ultrasonic vibration-assisted polishing (UVAP) method, a recently developed advanced processing technology, is widely used in the processing of brittle materials. This study uses molecular dynamics (MD) simulations to investigate the polishing behavior of diamond grits on SiC workpieces during the UVAP process. The frequency (f_z), amplitude (A_z), and dimensions of the vibration are varied to investigate various aspects of the material removal process. In the low-frequency region, the UVAP processing method exacerbates taper slips and dislocations in the workpiece. In the high-frequency region, f_z and A_z can improve the MRR by more than 32% and reach 2–4 times higher than that of traditional scratching, respectively. The surface morphology obtained using MD simulation is consistent with the experimental results. In the ultrasonic elliptical vibration assisted polishing (UEVAP) method, f_y not only causes a periodic and stable increase in temperature, which helps to transform atoms into an amorphous structure, but it also increases material removal rate (MRR) while decreasing friction factor and surface roughness. Appropriate increase of f_z reduces forces and improves stress distribution. A_z significantly increases MRR but results in a rough surface. In comparison to the UVAP process, the UEVAP method further improves MRR and produces smoother machined surfaces.

This study uses molecular dynamics (MD) simulations to investigate the polishing behavior of diamond grits on SiC workpieces during the UVAP process. The frequency (f_z), amplitude (A_z), and dimensions of the vibration are varied to investigate various aspects of the material removal process.