Apple Inc.
Process for reducing nickel leach rates for nickel acetate sealed anodic oxide coatings

Abstract:

Sealed anodic coatings that are resistant to leaching of nickel and nickel-containing products and methods for forming the same are described. Methods involve post-sealing thermal processes to remove at least some of the leachable nickel from the sealed anodic coatings. In some embodiments, the post-sealing thermal processes involve immersing the sealed anodic coating within a heated solution so as to promote diffusion of the leachable nickel out of the sealed anodic coatings and into the heated solution. The resultant sealed anodic coating is pre-leached of nickel and is therefore well suited for many consumer product applications. In some embodiments, a post-sealing thermal process is used to further hydrate and seal the sealed anodic coating, thereby repairing structural defects within the sealed anodic coating.