Study on surface integrity of RS-SiC under photocatalysis/vibration-assisted finishing

Abstract

Reaction-sintered silicon carbide (RS-SiC) is widely used in optical mirrors for space exploration. Maintaining surface integrity by obtaining both high surface finish and minimal subsurface damage is critical for achieving optimal performance. However, conventional machining processes struggle to meet these requirements because of high hardness and brittleness of RS-SiC. This paper presents a novel photocatalysis/vibration-assisted finishing technique and provides a systematic analysis of polished RS-SiC, including surface and subsurface characteristics. The involved process generates a softer, smoother, and amorphous oxide layer, significantly enhancing polishing efficiency and achieving a surface roughness of 0.25 nm in Ra. And the subsurface damage is minimized effectively. This study confirms that photocatalysis/vibration-assisted finishing is an eco-friendly ultra-precision polishing technology with the potential to achieve damage-free processing.