Abstract
In order to examine the mechanisms of wear by roll-formation wear experiments were made between rubber erasers which worn easily by roll-formation and glass disks. The necessary conditions for wear by roll-formation were determined, and the mechanisms of roll-formation were examined observing the rubbing surface.
At low contact pressure and low sliding speed wear rates of rubber erasers were low and wear by roll-formation did not occur. Then transferred films were only observed on the mated glass disk. If fragments were formed they were extended to films. These films were not so easily detached from the rubbing track.
Above critical contact pressures and critical sliding speeds wear by roll-formation took place and the wear rates were high. When the elongation, strength and hardness of rubber erasers were low, the rolls were also easily formed. Then the small fragments were made at the initial stage and travelled on the rubbing surface by rolling which contained slipping. They increased in size after joined together because each speed was different. Some fragments rolled the films. A few large fragments divided into some parts but the combination of fragments dominated the break-up of fragments. The enlarged fragments were detached in front of the rubber pin when about to re-enter the rubbing surface. Thus the wear rates were high when the wear by roll-formation took place.
