研究了三種典型的碳化硅光學材料CVD SiC、HP SiC以及RB SiC的材料去除機理與可拋光性，并對其進行了超光滑拋光試驗。在分析各種材料制備方法與材料特性的基礎(chǔ)上，通過選擇合理的拋光工藝參數(shù)，均獲得了表面粗糙度優(yōu)于Rq=2nm（采樣面積為0.71mm×0.53mm）的超光滑表面。試驗結(jié)果表明：研磨過程中，三種碳化硅光學材料均以脆性斷裂的方式去除材料，加工表面存在著裂紋以及材料脫落留下的缺陷;拋光過程中，CVD SiC主要以塑性劃痕的方式去除材料，決定表面粗糙度的主要因素為表面微觀劃痕的深度；HP SiC同時以塑性劃痕與晶粒脫落的形式去除材料，決定表面粗糙度的主要因素為碳化硅顆粒大小以及顆粒之間微孔的尺寸；RB SiC為多組分材料，決定其表面粗糙度的主要因素為RB SiC三種組分之間的去除率差異導(dǎo)致的高差。

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.