Design, development and tribological characterization of Ti-6Al-4V/hydroxyapatite composite for bio-implant applications

In the present research, a bio-composite material was initially designed and developed as per the requirement of prosthesis implants. Hydroxyapatite (HA) is considered as one of mostly used biomaterial due their unique characteristics of similarity in the composition of human bone and its bioactivity. Ti-6A1-4V is one of the foremost used materials in bio-implants due to their strength, wear resistance, corrosion resistance and biocompatibility. The addition of HA in Ti alloy substantially improves its bioactivity and biocompatibility. However, at the same time, the wear rate of bio-composite increases. In the present work, Ti-6Al-4V/hydroxyapatite composite was developed by powder metallurgy method. To evaluate the real-time tribological characterization, the biocomposite was processed against the Al2O3 counter-surface in the presence of phosphate buffered saline (PBS) as a lubricant. In terms of characterization, the pin-on-disk tribometer was used for the evaluation of wear rate and friction coefficients in the range of 5 N-30 N of load. Scanning electron microscopy (SEM) micrographs revealed that plastic deformation and the abrasion are the main mechanisms of biocomposite/Al2O3 system. The pull-out material from the biocomposite plays a negative role on the friction coefficient and wear rate.