Calcium phosphate film coating on titanium substrate by electrochemical deposition

Abstract

Calcium phosphate film on titanium substrate was achieved by electrochemical method in four different kinds of electrolyte. The pure titanium metal (99.99%) with 0.8 cm in width and 2 cm in length was used as a substrate and it was subsequently etched by 2M HF for 1 minute before electrochemical deposition. Calcium phosphate film could form at a different current density for each kind of electrolyte as follows: 10 mA/cm2for MCPM based aqueous solution, 20 mA/cm² for MCPM based aqueous solution with ions addition, 10 mA/cm² and 20 mA/cm² for MCPM based 20%V/V ethanol and 50%V/V ethanol solution, respectively. The variation in film thickness depended on the kind of electrolyte and deposition time. The major phase that appeared in the film from MCPM based aqueous solution was brushite in coexistence with monetite. Apatite was induced in the film using MCPM based aqueous electrolyte with ions addition of NaNO₃ and NaF. On the other hand, monetite was formed as a major phase under the electrolyte condition of MCPM based ethanol solution. The highest adhesion value of film to substrate that formed in MCPM electrolyte based aqueous solution investigated by balance beam scrape adhesion and Mar tester was 150 g. After incubation in R-SBF for interval times, the amorphous bone like apatite formed.