On the effect of counterface material and aqueous environment on the sliding wear of various PEEK compounds

Polyetheretherketone (PEEK) compounds containing carbon fibres (CF), glass fibres (GF), PTFE, and graphite, respectively, were exposed to unidirectional sliding against various counterparts (100Cr6, X5CrNi18-10, alumina, and bronze). Some of these tests were repeated in water. The stainless steel revealed the best results under dry conditions, whereas alumina was the best counterpart in water. The compound containing GF plus PTFE performed best under dry conditions. Under wet conditions, CF were superior to GF, which react very susceptibly to water. The aqueous environment usually accelerated the compound wear. Only in case of CF containing compounds sliding against alumina, the water lubrication reduced the wear rate.