Patent ID: 8663807

Claim:
An article having at least one metal surface comprised of aluminum or aluminum alloy and a ceramic oxide protective coating deposited on said metal surface according to a method comprising: A) providing an anodizing solution comprised of water, a phosphorus containing acid and/or salt, and one or more additional components selected from the group consisting of: a) water-soluble complex fluorides, b) water-soluble complex oxyfluorides, c) water-dispersible complex fluorides, and d) water-dispersible complex oxyfluorides of elements selected from the group consisting of Ti, Zr, Hf, Ge, B and mixtures thereof; B) providing a cathode in contact with said anodizing solution; C) placing an article having at least one metal surface comprised of aluminum or aluminum alloy as an anode in said anodizing solution; and D) passing at least one current selected from: a. a pulsed direct current having a peak voltage of 200 to 600 volts; and b. a non-pulsed direct current or an alternating current at voltage from 200 to 600 volts; between the anode and cathode through said anodizing solution for a time effective to form a ceramic oxide protective coating, containing phosphorus, on the at least one metal surface of the article; wherein said ceramic oxide protective coating is comprised predominantly of oxides of elements selected from the group consisting of Ti, Zr, Hf, Ge, B and mixtures thereof.