Effect of soot introduced between sliding ceramic surfaces

This study is carried out in order to understand the basics of soot lubrication using a ring-on-disk wear tester. When soot is introduced between sliding surfaces made of ceramic materials, it works most effectively in frictional conditions at around 300 C with SiC, Si3N4 and Si3N4-TiN. Ceramic surfaces rubbed with soot are smoother than the original ones, especially in the case of non-oxide ceramics. Reaction products formed on the surfaces are analyzed using an electron probe X-ray microanalyzer (EPMA). It is confirmed that SiO2 is produced on the surfaces of non-oxide ceramics during friction and wear, and the soot deposited on the sliding surface forms a thin film that reduces the wear rate and friction coefficient. 9 refs.