Silicon carbide sliding material

摘要

A slide material has a mainly coarse grained SiC matrix of pressure-less sintered SiC with a bimodal particle size distribution formed by prismatic SiC crystallite plates, 50-90 (preferably 60-90) vol.% of which have 100-1500 mu length and 10-50 (preferably 10-40) vol.% of which have 5 to less than 100 mu length. Preferably, the SiC crystallites consist of alpha silicon carbide and up to 2 wt.% Al and/or B. Also claimed is a process for producing the above slide material by mixing finely divided alpha SiC powder with sintering additives (preferably aluminium nitride and/or boron), pressing aids and optionally pore formers, pressing to green bodies, preheating at up to 1000 degrees C in a protective gas atmosphere, sintering at 2040-2090 degrees C to produce sintered bodies of 90-99 % theoretical density and then tempering at a grain growth temperature of 2100-2220 degrees C for 20-60 mins.