Preparation of ceramic-metal coatings

A metal substrate, e.g. titanium, having a calcium phosphate coating, particularly hydroxylapatite, and containing a metal such as cobalt, codeposited on the substrate by electrolyzing a cobalt salt, particularly cobalt sulfate, liquid electrolyte having a calcium phosphate material, particularly hydroxylapatite, suspended therein, employing a cobalt anode and the metal substrate as cathode. The particles of cobalt so codeposited with the particles of calcium phosphate material, e.g. hydroxylapatite, hold the latter particles strongly on the substrate metal. If desired, a second coating of the pure calcium phosphate material, e.g. "hydroxylapatite", optionally can be applied over the codeposited hydroxylapatite-cobalt coating. The calcium phosphate coated metal substrate of the invention, particularly the codeposited "hydroxylapatite"-cobalt coating, on a titanium or cobalt-chromium substrate, has particular value for application as medical implants, e.g. as hip prosthetics, and for high temperature high stressed applications.