Electrodeposited anodic oxide coatings were produced on Ti-6Al-4V substrates using aqueous electrolytes containing dissolved calcium and phosphorus. Different coatings were produced by varying the time periods. The coatings contained TiO as the major phase and contained very small quantities of calcium and phosphorus. All the coatings were less than 200 nm thick. A point defect model is obeyed by all the coatings.