Interference coloring of thick, porous, oxide films

摘要

Porous metal oxide layers having a color due to visible light interference effects are disclosed. In particular embodiments the porous metal oxide layers are formed using an anodizing processes, which includes a porous metal oxide layer forming process and a barrier layer thickening process. The barrier layer thickening process increases a thickness of a barrier layer within the porous metal oxide layer to a thickness sufficient to and cause incident visible light waves to be reflected in the form of a new visible light waves, thereby imparting a color to the porous metal oxide layer. Methods for tuning the color of the porous metal oxide layer and for color matching surfaces of different types of metal substrates are described.

主权项

1. A housing for an electronic device, the housing comprising:
an aluminum alloy substrate; and an anodic coating positioned on the aluminum alloy substrate, the anodic coating including:
a porous layer having pores with pore terminuses, anda non-porous barrier layer disposed between the porous layer and the aluminum alloy substrate, the non-porous barrier layer having a thickness defined by the pore terminuses and the aluminum alloy substrate, wherein the thickness of the non-porous barrier layer is configured to impart a color to the anodic coating by thin film interference, the thickness ranging from about 175 nm to about 500 nm, wherein the second color imparted by the non-porous barrier layer is characterized as having a measured b* value ranging between about 0 and about −6 and a measured a* value ranging between about 0 and about −1.5.