Mechanical properties and wear behaviour of alumina/tricalcium phosphate/titania ceramics as coating for orthopedic implant

This research work reports the impact of adding synthesized Tricalcium Phosphate (beta-TCP) and commercial Titania powder (TiO2) on the mechanical and tribological properties of Alumina (Al2O3). In fact, the commercial Al2O3 mingled with beta-TCP and commercial (TiO2) to obtain a mixture which considered as a bioactive coating that may be used in orthopedic implants. Representative bioceramic samples of such blends were prepared with different formulations and then tested using numerous methods and techniques. Mechanical properties, hardness and fracture toughness were evaluated by semi-circular bending (SCB) and instrumented indentation tests. A pin-on-disk tribometer was retained to ensure friction and wear experiments against zirconia ball. A 2D profilometer was used to measure and estimate the wear volume generated after sliding tests. Scanning electron microscopy (SEM) was equally used to examine wear mechanisms for worn surfaces of the tested samples. From the main results, it was found that the best wear resistance was measured for Al2O3-10 wt % TCP-5 wt% TiO2 formulation under dry conditions. Also, the lowest friction coefficient was found to correspond to the same biocomposite. Finally, the best mechanical and fracture properties, in terms of micro-hardness and fracture toughness, were obtained for Al2O3-10 wt% TCP -5 wt% TiO2 composition.