Biofunctional calcium titanate coating on titanium by simple chemical treatment process using calcium-hydroxide slurry—Effects of the heating temperatures

The present study investigates the effect of the heating temperature on the characteristics of the surface layer in a simple treatment process using calcium-hydroxide slurry. Furthermore, biofunctions of the treated titanium surfaces, such as bioactivity in a simulated body fluid and corrosion resistance under a bio-environment, are also investigated. Our treatment process using calcium-hydroxide slurry is as follows: a titanium substrate is buried in calcium hydroxide slurry, and the slurry is then heated in air. The calcium hydroxide slurry was prepared by mixing of calcium hydroxide powder and water. When treated at heating temperature beyond 873 K, a crystallized calcium titanate coating is formed on a titanium substrate and further, the thickness increases with the increase of heating temperature. On the crystallized calcium titanate coating, calcium phosphate is precipitated in a simulated body fluid; therefore, the treated titanium surface has bioactivity. Furthermore, anodic current density of the treated surface is 10–103 times lower than that of the non-treated surface.