Antifriction and Mechanical Properties of the Thermoplastic Matrix of Polyetheretherketone-Based Composites

The structure and mechanical and tribological properties of composites based on a thermoplastic matrix of polyetheretherketone (PEEK) loaded with carbon fibers of various (nano-, micro and millimeter) sizes were studied. The research is aimed at developing composites applicable for use both in metal–polymer and ceramic–polymer tribojoints, including endoprostheses. It is shown that the surface layer of the PEEK composite loaded with carbon nanofibers can play a damping role in the friction process. This ensures an increased in wear resistance by 1.5–2 times. Carbon fibers of micron and millimeter length play a reinforcing role. Thus, the wear resistance of PEEK composites can be increased up to seven times in metal–polymer tribojoints, while this is reduced by 16 times in ceramic–polymer tribojoints. It is shown that by choosing the type and weight fraction of fiberlike fillers (carbon nano/micro/millimeter fibers) in PEEK matrix, the tribological and mechanical properties can be purposefully increased. This makes it possible to expand areas of application and product range for tribojoints in mechanical engineering and medicine, including those formed using additive technologies.