Friction and Wear Behaviors of Rubber Sealing Material against Rough Surface under Starved-Oil Condition

Tribological tests for nitrile butadiene rubber (NBR) against SiC abrasive paper with different surface roughness were carried out on an UMT-3 multi-function friction and wear tester. The tribological characteristics of the rubber sealing material against rough surface under starved-oil condition were systematically performed. The time-varying of fiction coefficient, friction-reducing degree and friction-reducing durability were discussed, and the damage mechanism of rubber against rough surface under starved-oil condition was revealed. The results show that friction-reducing extent and durability of lubricant were strongly dependent on surface roughness of the counterpart. With the decrease of the surface roughness, the friction-reducing degree increased slowly and then increased rapidly, while durability of friction-reducing decreased firstly and then increased gradually. Meanwhile, friction-reducing durability of oil lubrication was superior to grease lubrication. For the wear mechanism, with the decrease of the surface roughness, the worn surface of rubber material under starved-oil condition shifted gradually from severe abrasive wear with ploughing characteristic into mild abrasive wear. However, under without lubrication, typical abrasive wear of rubber material was transformed into pattern wear, eventually the wear mechanisms were adhesive wear.