The effects of copper particles and oleic acid on the friction and wear characteristics of ceramics in ethanol

Abstract For the combinations of a Si 3 N 4 pin and four kinds of ceramic disk (SiC, Si 3 N 4 , Al 2 O 3 , ZrO 2 ), a friction and wear test was carried out in three kinds of lubricants (temperature: 20.0 ± 1.0 °C) [ethanol, ethanol + copper particles (1 wt.%; average diameter d = 236 nm), and ethanol + copper particles + oleic acid (1 vol.%)] in order to find the lubricity of the copper particles and oleic acid. A topographical analysis was also performed on the micro-asperities of the wear surfaces to estimate the behavior of the copper particles and oleic acid, and the degree of surface damage. As a result, the following facts were found: 1. 1. The addition of copper particles in ethanol decreased the wear rates of the mated ceramics. The lubricity of the additives and the wear rates could be estimated to some extent by analysis of the surface topographies. 2. 2. The addition of copper particles and oleic acid in ethanol caused the wear rates of both ceramics to decrease considerably more than that of copper particles only. But the mean coefficient of friction for the both additives was greater than that for no additives.