Friction and wear mechanism of short-cut aramid fiber and silica reinforced elastomers

Abstract

Important phenomena during sliding contact of elastomeric materials are friction and wear. Wear reduction of elastomers can be achieved by minimizing the propagation of cracks in the elastomer during sliding contact. Adding fillers like silica and fibers is a way to reduce the propagation of cracks and as a result reduction of wear. In the present study, the wear processes of short-cut aramid fiber reinforced elastomers as a function of sliding distance and their relation to friction are investigated. Two different types of systems are considered, i.e. (1) elastomers reinforced by solely short-cut aramid fibers and (2) elastomers reinforced by short-cut aramid fibers and silica. A pin-on-disc tribometer and a microscope are used to analyze the friction and wear mechanisms of the elastomeric composites in sliding contact with a granite counter surface. The results show that the coefficient of friction of the composites consists of different stages, these stages are influenced by the wear processes during sliding. For elastomers which are reinforced by short-cut aramid fibers and silica, a higher energy input is needed to achieve all stages since the presence of silica in the elastomer matrix increases the resistance of matrix particle detachment. A general friction behavior of short-cut aramid fiber and silica reinforced elastomers is proposed.