Friction and wear of short-fibre-reinforced rubber composites under various sliding speeds and loads

Abstract

Friction and wear properties of short-fibre-reinforced chloroprene rubber composites were examined in the longitudinal (L), transverse (T) and normal (N) directions of the oriented polyamide fibres. The experiments were conducted for various sliding speeds of rubbing against abrasive papers. The rubbing experiments were also conducted under various loads, using both metal gauze and abrasive paper. When rubbed against abrasive paper and metal gauze, the wear rates of the short-fibre-reinforced rubber (SFRR) composites were lower than those of the unreinforced chloroprene rubber. A marked difference in the wear rates for these two specimens was observed when each was rubbed against metal gauze. A considerable difference was also observed when each was rubbed against abrasive paper. The minimum wear rates were obtained for rubbing in the N direction of the SFRR under the conditions examined. The maximum wear rates were observed for rubbing in the T direction. The wear rate for rubbing in the L direction exhibited medium values. The load dependence of the wear rates was greater for the SFRR than for the unreinforced rubber when rubbed against metal gauze. However, the load dependence of the wear rates for the SFRR was similar to that for the unreinforced rubber when rubbed against coarse abrasive paper. With decreasing load, the wear states of the unreinforced rubber rubbed against metal gauze changed from pattern abrasion to milder wear that arose from the hardening of the rubber surface. The speed dependence of the wear rate and frictional coefficient was very small for rubbing against coarse abrasive paper. When rubbed against fine abrasive paper, the variation of the friction with sliding speed was observed to be peak-shaped for the SFRR rubbed in both the N and L directions. The peak of friction was manifested by the transfer of rubber to the mated abrasive paper. Following the transfer of rubber, the wear rate decreased. Abrasion patterns were observed only for the unreinforced rubber rubbed against fine abrasive paper. The spacing of the patterns became wider with decreasing sliding speeds.