Investigation of photocatalysis/vibration-assisted finishing of reaction sintered silicon carbide

Abstract

Reaction-sintered silicon carbide (RS-SiC) is an ideal material for spacecraft reflectors due to its excellent mechanical properties. However, its high hardness, brittleness, and multiphase nature pose significant challenges to conventional polishing techniques. To address this, photocatalytic modification and vibration assistance have been employed to enhance both precision and efficiency in the polishing process of RS-SiC. In this work, the oxidative properties of RS-SiC surface during photocatalytic reaction are elucidated using molecular dynamics simulation coupled with X-ray photoelectron spectroscopy analysis. Parameters including concentration of TiO₂ and H₂O₂, frequency, and amplitude of vibration table are optimized, indicating that the TiO₂ concentration serves as the primary influence on the oxidation rate. Further investigation into the effects of spindle rotation speed and polishing pressure during the material removal process shows that roughness is minimized when material removal rate equals oxidation rate. Ultimately, on the basis of optimized parameters, a material removal rate reaching 2.1 μm/h and surface roughness of 0.26 nm in Ra are achieved. This study provides significant guidance for the further application of photocatalysis/vibration-assisted finishing technology.