Carbon-fibre-reinforced-PEEK and silicon doped amorphous carbon as a potential tribopair for implant application

Studies pertaining to the evaluation of temperature rise in bio-tribopairs are scarce. The present work analyses the application of Si-doped amorphous carbon (Si:a-C) and carbon-fibre-reinforced-PEEK (CFRPEEK) as a potential metal-on-polymer acetabular articulation. The structure of the materials was studied using XRD and Raman spectroscopy and the mechanical behaviour of the Si:a-C film was evaluated using nanoindentation test and Rockwell-C indentation test. Si incorporation resulted in improved hardness and elastic modulus of a-C film along with appreciable H/E and H-3/E-2 attributes. The structure of Si:a-C film presented SiC phase with reduced sp(2) clustering which results in lower graphitisation. CFRPEEK showcased crystalline structure with disorderness induced due to the introduction of carbon fibre. What is more, during lubricated sliding, the temperature rise in the sliding interface was obtained using thermocouple installed in the CFRPEEK counterbody near the sliding vicinity. The results showed low friction coefficient due to the formation of SiOx phase during sliding with low temperature rise having coefficient of 2.1. Si:a-C film underwent low fracture with patches of delamination and CFRPEEK suffered fibre pull-out and tearing. Further studies on the biological activities such as cell adhesion and bacterial adhesion can mainstream the application of these materials for implants.