Wear and rolling contact fatigue of PEEK and PEEK composites

Wear and rolling contact fatigue were investigated on unfilled PEEK and on three PEEK short fiber reinforced composites. For this aim, roller-shaped specimens were subjected to rolling contact tests at different contact pressure levels. Wear rate-pv product and contact pressure-life diagrams were obtained, depending on material hardness. Microscopic observations of rolling contact surfaces and sections of the rollers highlighted damages at two different scales, surface and bulk, leading independently to wear and rolling contact fatigue. These damages were also of different typology for unfilled PEEK and composites: micro-pitting and deep transversal cracks occurred on unfilled PEEK rollers, while delamination and spalling phenomena where found on composite rollers.