摘要 |
A method for producing a multi-layer anodic coating on a metal is described. The method comprises the steps of (i) placing the metal in a first electrolytic solution and applying a current to form a first anodic layer having a barrier region; (ii) reducing the applied current to cause a reduction in thickness of the barrier region; and (iii) placing the metal in a second electrolytic solution and applying a current to form a second anodic layer. |