Effect of oxidation inhibitor on the low energy tribological behavior of carbon-carbon composites

In this study, the tribological performance of carbon-carbon composites impregnated with different amounts of MoSi₂ as an oxidation inhibitor were investigated. The results of the friction tests indicated that the carbon-carbon composites underwent an abrupt transition of the coefficient of friction at the frictional temperature range of 150-180°C. And the composites made with MoSi₂, exhibited lower frictional coefficient and wear rate in comparison with the composites made without MoSi₂. The composites made with 4 wt% MoSi₂ showed an improvement in activation energies for wear resistance when compared with the other composites under the present condition. These results were probably due to the consequence that the friction and wear properties of carbon-carbon composites are sensitive to the friction temperature and can be largely dependent on the adhering force between fibers and matrix-MoSi₂, the reduction of porosity, and the formation of a lubricative, powdery, debris film, formed on the friction surfaces of the carbon samples.