Characterization and stability of hydroxyapatite coatings prepared by an electrodeposition and alkaline-treatment process

Hydroxyapatite (HA) coatings on titanium alloy substrates were prepared by an alkaline treatment of electrodeposited precursors. The structure, residu al stress, and bond strength of the coatings were investigated. Test result s showed that the coatings processed in this study exhibited fairly low ten sile residual stress, high crystallinity, and were free of an amorphous pha se. The bond strength of the coatings increased with the decrease of curren t density in the range of 0.2-15 mA/cm(2), and reached 14 MPa at 0.2 mA/cm( 2). Evaluation of the coatings was performed together with the evaluation o f the plasma-sprayed HA coatings immersed in distilled water. It was reveal ed that the dissolution and bond strength degradation of the coatings were much lower than those of the plasma-sprayed HA coatings. (C) 2000 John Wile y & Sons, Inc.