Tribological studies of Epoxy and its Composites Coated on Steel in Dry and Lubricated Conditions for Green Tribology

摘要

Pure epoxy and its composite films were coated on steel substrates (shaft) and tested under dry and lubricated conditions. 10 wt.% of graphene or graphite was added to the polymer. Friction and wear experiments were conducted on a ball-on-cylinder tribometer. Under dry condition at 3 N normal load and 0.63 m/s (300 rpm) sliding speed, wear life of epoxy/graphene coating was approximately 5 times that of pure epoxy or epoxy/graphite coating. The steady-state coefficient of friction was in the range of 0.18 for both pure epoxy and epoxy/graphene whereas it was higher at 0.27 for epoxy/graphite. For the lubricated sliding using base oil (SN 150), epoxy/graphene showed nearly no wear after 30,000 cycles of sliding at 3 N load and 0.63 m/s speed, epoxy/graphite shows minimal wear whereas pure epoxy shows deep wear marks. The coefficient of friction in lubricated sliding remained in the range of 0.06-0.09 with epoxy/graphene giving lower value compared to the other two coatings.