Bioactive Titanium-Hydroxyapatite Composites by Powder Metallurgy Route

Abstract

Titanium (Ti) and its alloys have become the most promising biomaterials due to their low elastic modulus, high corrosion resistance, and relatively long-lasting ability in a physiological environment. Bioactive implants enhance the tissue interactions at the surface of the implants and promote a higher healing rate. However, titanium exhibits bio-inert nature. Hence in the present study, hydroxyapatite (HA), a well-known bioceramic, has been selected to disperse into Ti with an aim to develop bioactive Ti-based implants. Ti-HA composites with 5% and 10% HA were successfully produced by high-energy ball milling for 20 h followed by sintering (at 850 °C). Fine-grained composites were successfully produced and were found to be free from any impurities. The composites were immersed in simulated body fluid (SBF) for 4 weeks to investigate the in vitro bioactivity. From the XRD studies and scanning electron microscope observations, the presence of HA in the composite enhanced the bioactivity as reflected with higher Ca/P mineral phases on the surface of the composites compared with pure Ti substrate. From the results, it can be concluded that the bioactive nature of Ti can be enhanced by reinforcing HA to manufacture medical implants with a higher healing rate.