Electrochemical corrosion and bioactivity of titanium–hydroxyapatite composites prepared by spark plasma sintering

► We investigated corrosion resistance and bioactivity of Ti–HA composites. ► The surface microstructure related with corrosion behavior was studied by FE-SEM. ► Superior corrosion resistance was obtained for Ti containing 0–10% HA. ► Higher HA content decreased the corrosion resistance. ► Bioactivity test in SBF showed the growth of nanohydroxyapatite layer and particles. The corrosion resistance and bioactivity of titanium–hydroxyapatite (Ti–HA) composites prepared by mechanical alloying (MA) followed by spark plasma sintering were investigated. Potentiodynamic polarization tests showed that Ti composites containing 0–10% HA exhibited higher corrosion resistance than commercially pure Ti. An increase in HA concentration (20–30%) decreased corrosion resistance owing to the craterlike defects induced by ceramic particle detachment. Increasing MA time significantly reduced defect density and improved corrosion resistance. Bioactivity test on Ti HA composites in simulated body fluid revealed the growth of a nano-HA layer, which indicates the high potential of Ti–HA composites for application in biomedical implants.