Process for simultaneous electrodeposition of at least a two component alloy system of cobalt and chromium on a substrate, by providing an aqueous solution of divalent cobalt and trivalent chromium ions and containing ethylenediaminetetraacetic acid, at a pH of about 3 to about 5, electrolyzing the solution in an electrolyte cell containing an anode and a cathode, and codepositing cobalt and chromium on the cathode, e.g. titanium, as substrate. According to a preferred embodiment molybdenum-containing ions are also added to the electrolyte, resulting in codeposition of an alloy of cobalt, chromium and molybdenum. In another embodiment, a calcium phosphate ceramic such as hydroxyapatite (HA)is added to the above electrolyte solution, resulting, e.g. , in a codeposit of the calcium phosphate material, e.g. HA, and an alloy of cobalt, chromium and molybdenum. In still another embodiment, a calcium phosphate material such as HA, which has been previously attached to a substrate by sintering, is fixated by simultaneous electrodeposition of cobalt-chromium-molybdenum alloy, such codeposits having utility for improvement of medical implants.