Smoothing of reaction sintered silicon carbide using plasma assisted polishing

We proposed a novel polishing technique named plasma assisted polishing (PAP) for the finishing of some difficult-to-machine materials, such as diamond, silicon carbide, sapphire and so on. In this work, PAP was applied to the smoothing of reaction sintered silicon carbide (RS-SiC) surface. Experimental results indicated that a higher oxidation rate led to a smoother surface. The smoothing mechanism was discussed based on the relationship between oxidation rate of RS-SiC and polishing rate of oxide layer. Through increase in the oxidation rate and decrease in the polishing rate, a smooth surface with 11.42 nm p–v and 0.91 nm rms was obtained. The amount and depth of scratches also decreased after PAP using ceria abrasives compared with the surface polished by diamond abrasives.