以纯碳粉作为原料、酚醛树脂为粘结剂、聚乙烯醇(PVA)为造孔剂，通过液相渗硅制得碳化硅/石墨复合陶瓷材料，考察了PVA的含量对复合陶瓷烧结性能和显微结构的影响。研究发现，以PVA为造孔剂，高温可以使PVA挥发，在坯体中形成空腔，有利于硅的渗入，并与碳进行反应，从而形成碳化硅，最终制备出碳化硅/石墨复合陶瓷材料；随着PVA含量的增加，碳化硅/石墨复合陶瓷烧结性能和力学性能提高，当PVA达到15%时，各项性能达到最佳。此外，PVA的含量不影响复合陶瓷的物相组成。所制备的碳化硅/石墨复合陶瓷材料可应用于机械密封等领域。%Silicon carbide/graphite composite ceramic was prepared by liquid silicon inifltration processing using pure carbon powder as raw material, phenolic resin as binder, and polyvinyl alcohol as pore forming agent. The inlfuence of polyvinyl alcohol (PVA) content on the sintering behavior and the microstructure of the ceramic was investigated. The results show that PVA volatilized during the sintering and generated the porous structures in the body, which was beneifcial to the permeation of liquid silicon and the reaction between silicon and carbon powders to form the SiC/C composite ceramics. The sintering and mechanical properties of the SiC/C composite ceramic improved with the increase of PVA content. When 15% PVA was added, the properties of the SiC/C composite ceramics were the best. Whereas, the content of PVA did not affect the phase composition of the SiC/C composite ceramic. The resultant silicon carbide/graphite composite ceramic could be applied in the ifeld of mechanical seals.
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