The effect of the transfer film on the friction and wear of dry bearing materials for a power plant application

Friction and wear tests have been carried out for a number of commercial dry bearing materials containing polytetrafluoroethylene (PTFE), MoS₂ or graphite for a specific turbogenerator application. The effect of operating temperatures up to 300 °C has been investigated. The performance of the materials was strongly related to the formation and stability of a transferred film. PTFE-containing materials offered the most favourable performance over a wide temperature range; the wear rate obeyed a modified form of Archard's adhesive wear law. A simple model for the running-in behaviour of these materials is proposed.