Comparative Investigation on the Friction and Wear Behaviors of Carbon Fabric-Reinforced Phenolic Composites under Seawater Lubrication

Carbon fabric-reinforced phenolic composites were prepared by dip-coating and hot press-molding techniques. The interlaminar shear strength (ILSS) of phenolic composites was determined by a three-point bending test on a universal material testing machine and their friction and wear behaviors under dry friction, pure water, and seawater lubrication were investigated comparatively using a block-on-ring test rig. Experimental results showed that carbon fabric-reinforced phenolic composite with 30 wt% resin had the best ILSS and tribological properties, and the ILSS of phenolic composites decreased with increasing content of resin. When experiencing immersion in pure water and seawater for 24 h, the ILSS of phenolic composites decreased greatly, and this decrease was in particular more obvious after immersion in pure water. In addition, compared to dry sliding condition, phenolic composites exhibited much better tribological properties under seawater lubrication but worse tribological properties under pure water lubrication. The differences in the tribological behaviors of phenolic composites were determined by two competitive effects of aqueous medium, including cooling, lubricating and washing effect, and plasticization effect. Moreover, the wear mechanisms of phenolic composites under dry friction and lubrication with aqueous media were adhesive wear and slight abrasive wear, respectively.