Studies on the friction and wear characteristics of rubber-based friction materials containing carbon and cellulose fibers

The present study was an attempt to examine the effects of carbon and cellulose fibers on the tribological characteristics of rubber-based friction materials (RBFMs). A fiber free RBFM as a reference material and a series of fiber included RBFMs at different volume fractions were prepared by two-roll mill. The friction tests were performed at different sliding velocities and various drum temperatures. The mechanical properties and surface microstructure of friction specimens were also examined. It was revealed that the carbon fiber influences slightly the coefficient of friction (COF) of RBFM but it improves the wear resistance and the fade behavior considerably. It reduces the drum temperature as well. Cellulose fiber though offered high COF but it proved to be destructive from the fade behavior and wear rate point of view due to its weak thermal stability. It was found that the rubber-to-glass transition, which occurred at high sliding velocities, influences the COF, wear rate, and fade behavior of the RBFMs significantly for both fiber free and fiber-containing systems.