| abstract |
A ceramic coating is formed on a conductive article by immersing a first anodic electrode, including the conductive article, in an electrolyte comprising an aqueous solution of alkali metal hydroxide and an alkali metal silicate, providing a second cathodic electrode in contact with the electrolyte, and passing an alternating current from a resonant power source through the first electrode and to the second electrode while maintaining the angle φ between the current and the voltage at zero degree, while maintaining the voltage within a predetermined range. The resulting ceramic coated article comprises a coating which includes a metal, silicon, and oxygen, wherein the silicon concentration increases in the direction from the article surface toward an outer surface of the ceramic coating surface layer. |