Effect of oxygen plasma-treated carbon fibers on the tribological behavior of oil-absorbed carbon/epoxy woven composites

In this study, woven type carbon fibers were plasma-treated using oxygen gas, and the effect of the plasma treatment on tribological behavior of oil-absorbed carbon/epoxy woven composites was investigated. Chemical changes on the surface of the woven carbon fibers due to oxygen plasma treatment were determined by XPS analysis. Ball-on-disk wear tests were performed on untreated and plasma-treated carbon/epoxy woven composites that were fully oil absorbed. It was found that carbonyl functional groups were created on the carbon fibers due to oxygen-plasma treatment. In addition, the friction coefficient and wear rate of the plasma-treated carbon/epoxy composites were lower than that of untreated carbon/epoxy composites. SEM examination of the worn surface showed that the improved wear properties of the plasma-treated carbon/epoxy composites were attributed to enhanced adhesive strength, caused by the carbonyl functional groups between the carbon fibers and epoxy.