Influence of Oxidation Inhibitor on Carbon-Carbon Composites: 6. Studies on Friction and Wear Properties of Carbon-Carbon Composites

The friction and wear properties of carbon-carbon composites made with different weight percent of MoSi₂ as an oxidation inhibitor were investigated using a constant speed wear test apparatus in an oxidation environment. The results indicated the carbon-carbon composites undergoing an abrupt transition of friction coefficient, from low-friction behavior (μ=0.15-0.2) during normal wear regime to the high-friction behavior (μ=0.5-0.6) during dusting wear regime at the factional temperature range of 150-180 °C. The existence of temperature-dependent friction and wear regimes implied that the performance of specimen made with carbon-carbon composites was markedly affected by the thermal properties of the composites. The carbon-carbon composites filled with MoSi₂ exhibited two times lower coefficient of friction and wear rate in comparison with the composites without MoSi₂. Especially, the composites containing 4 wt% MoSi₂ filler showed a significantly improved activation energy for wear due to the reduction of both the porosity and powdery debris film formation on sliding surface when compared to those without MoSi₂.