Wear Performance of High Performance Polymeric Bearing Materials

Previously, a wear-testing standard was defined that is relevant to high performance bearing materials under realistic automotive powertrain conditions [1]. Using this experimental protocol, studies were extended to include the following bearing grade materials, 450FC30 pol-yaryletherketone (PAEK), polyimide (PI), polyamideimide (PAI) (as received and annealed), polyphthalamide (PPA) and a PTFE bronze sinter. Prior to tribological testing, surface defects or skin/core moulding effects were removed using a defined break-in protocol [1]. The data allowed the bearing materials to be ranked in terms of their wear performance. The PAEK and PI exhibited low wear rates suitable for automotive powertrain applications. The PTFE sinter bronze initially exhibited low wear rates but failed catastrophically after short periods of unlubricated sliding contact. The materials PAI and PPA all gave high wear rates at the lowest pv conditions and consistently failed at the higher pv conditions.