Friction and wear mechanisms of phenolic-based materials on High Speed Tribometer

Abstract : This work takes place in the understanding of the friction and wear mechanisms occurring in reinforced phe-nolic materials, widely used in organic braking pads. As the matrix is filled with a large variety of particles, the phenomena in the contact zone are complex and multi-physic. In a first approach the reinforcement is restricted to spherical steel particles with diameters in the range of the fibbers size. The influence of the sliding speed, the mean normal pressure and the contact temperature are examined and the benefits of using this kind of particle is as well discussed. The tribological tests are performed on a newly developed High Speed Tribometer designed to reproduce braking conditions. The results show that temperature is the most influential parameter, leading to a decrease of the friction coefficient. They further indicate that reinforcement pushes the loss of efficiency to a higher temperature. Optical observations and profilometer analysis show that the wear mechanisms are clearly dependent on friction conditions. These results improve our knowledge of wear debris formation and conditions leading to particle debonding in phenolic matrix material.