I see this done a lot but doesn't a layer of aluminum oxide form preventing corrosion? If left unplated, will electrical performance of the unit installed in the chassis change over time?
Aluminum alloys in general have good corrosion resistance in certain environments and poor corrosion resistance in other environments. Anodizing is a process option for some Al alloys, used to built up thicker oxide surface layer. By controlling the anodizing process, the layer can be made porous so that it accepts dyes. Therefore, some Al alloys can be coated to almost any color of the rainbow. In electrical connections, Al is not generally used because the oxide layer is an insulator. Consult your friendly neighborhood metallurgist for more details.
