关键词: 碳化硅；抛光；去除机理；表面粗糙度

Abstract:

Super-smooth polishing experiments were carried out herein to study the polishing mechanisms and polishability of three types of silicon carbide materials: CVD SiC (chemical vapor deposition silicon carbide), HP SiC(hot-pressed silicon carbide) and RB SiC(reaction-bonded silicon carbide). A surface roughness of better than 2nm Rq (0.71mm×0.53mm) was achieved by analyzing the characteristic of each material and selecting processing parameters for each material. The experimental results indicate that during the lapping process, three types of silicon carbide materials are all removed by brittle fracture, and there exist surface cracks and pits caused by materials being pulled out on the surfaces. During the polishing process, CVD SiC is removed mostly by plastic scratches, thus the dominant factor of the surface roughness is the depth of the scratch on the polished surface; HP SiC is removed by plastic scratch and grains being pulled out at the same time, and the dominant factors of the surface roughness are the sizes of the SiC particles and the micropores between the particles; RB SiC is removed mostly by plastic scratches, and the dominant factor of the surface roughness is the height difference between the three components of RB SiC because of their different material removal rates.

Key words: silicon carbide；polishing；removal mechanism；surface roughness