Abstract
Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy was soaked in 1M-NaOH solution and then 100mM-CaCl2 solution. About 4 atom % Na+ ions were incorporated into the surface of the TNTZ alloy by the NaOH treatment, and completely replaced with Ca2+ ions by the CaCl2 treatment. The Ca-doped TNTZ alloy was subsequently heat-treated at 700°C for 1h and soaked in water at 80°C for 24h. Thus treated TNTZ alloy formed an apatite on its surface in a simulated body fluid within 3 days.