Short carbon fiber (SCF) reinforced epoxy composites with different SCF contents were developed to investigate their tribological properties. The friction coefficient and wear of the epoxy composites slid in a circular path against a steel pin inclined at 45° to a vertical axis and a steel ball significantly decreased with increased SCF content due to the solid lubricating effect of SCFs along with the improved mechanical strength of the composites. The scanning electron microscope (SEM) observation showed that the epoxy composites had less sensitive to surface fatigue caused by the repeated sliding of the counterparts than the epoxy. The tribological results clearly showed that the incorporation of SCFs was an effective way to improve the tribological properties of the epoxy composites.

The mechanical and tribological properties of epoxy composites modified with microencapsulated wax lubricant and multi-walled carbon nanotubes (MWCNTs) were investigated. The increased soft microcapsules embedded in the epoxy matrices were responsible for the reduced micro-hardness and Young’s modulus of the epoxy composites. It was found that the friction of the epoxy composites greatly decreased with increased microcapsule content due to combined lubricating effects of the both wax lubricant and MWCNTs. As a result, the wear of the epoxy composites apparently decreased with increased microcapsule content.