| 摘要 |
PROBLEM TO BE SOLVED: To obtain a composite ceramic having improved fractional toughness and sliding characteristics by allowing a specific proportion of carbon to be included in silicon carbide and regulating the peak area ratio of laser Raman spectrum intensities of the crystal phase to the amorphous phase of the carbon so as to be within a specific range. SOLUTION: This composite ceramic contains 16-40 pts.wt. carbon based on 100 pts.wt. silicon carbide. The peak area ratio of laser Raman spectrum intensities of the crystal phase to the amorphous phase of the carbon is 0.1-10.0. Preferably, the silicon carbide has >=95 wt.% purity and is a powder with <=5 μm particle diameter. The carbon can be formed from a suitable carbon source in a manufacturing process, and the carbon source is preferably a furan resin, a phenol resin, a coal-tar pitch or the like. The composite ceramic is obtained by wet-mixing of the silicon carbide, the carbon source and an optional additive, calcining the wet-mixed product in an inert atmosphere at 400-800 deg.C to change the carbon source to the carbon, granulating the calcined material and firing the granulated material. The composite ceramic is suitable for a sliding part such as a bearing retainer and a mechanical seal. |
