Friction behaviors and wear mechanisms of multi-filler reinforced epoxy composites under dry and wet conditions: Effects of loads, sliding speeds, temperatures, water lubrication

Polymer composites have been extensively used as marine engineering structures under extreme environmental conditions for their mechanical/thermal stability and special self-lubricating performance. In the present paper, the multi-fillers reinforced epoxy composites (MFREC) had been prepared and analyzed. The mechanical, thermal properties, friction behaviors and wear mechanisms of MFREC were systematically investigated. The research results showed that the increase (98.46%) of MFREC tensile toughness was mainly attributed to improvement of tensile strength (9.56%), tensile modulus (22.07%), and elongation at break (39.09%) due to multi-fillers reinforcement and its compatibility with the epoxy matrix. Then, increases in loads and temperatures reduced frictional coefficients at the expense of wear rate and line roughness of MFREC due to the change in contact state (from elastic to plastic state). Additionally, effects of sliding speeds and water lubrication on MFRCE were not obvious compared to loads and temperatures owing to the formation of transfer layer and lubrication of water film. Furthermore, among the several influencing factors studied for tribological changes, MFREC was the most sensitive to the load effect due to the higher shear force of applied-load steel-ball by a tangential displacement, temperature second, sliding speed third and water lubrication last because of the lubricating effect and heat dissipation function of water film.