Characterization of Ti-HA composite fabricated by mechanical alloying

• Nano and microcomposites of titanium–hydroxyapatite are fabricated through milling process.
• Effects of composition, milling time and particle size on composite characteristics are studied.
• Increasing HA content decreases the density of the composites and enhances the surface hardness.
• Surface roughness is found to be a direct function of HA content.

Titanium (Ti) and its alloys possess suitable mechanical characteristics for utilization in orthopedic implants. However, their poor integrity with native tissues is a major challenge in their clinical application. Composite structures of Ti and hydroxyapatite (HA) can be used to promote the bone ingrowth and integration of the implant with the surrounding tissue. Here, we report the fabrication of Ti-HA nanocomposite powders using a high energy planetary ball mill. We investigate the effects of fabrication parameters including HA content (10–30% w/w), milling time (20 and 50 h), and HA particle size (50 nm and 15 μm) on the characteristics of the fabricated composites. In particular, we determine the samples hardness, sintering density, surface roughness and topography for different conditions. The results show that the addition of HA to Ti decreases the sintering density and enhances the surface hardness. Also, we observe a direct relationship between HA concentration in the Ti matrix and the surface roughness.