Anodize

From GAWDAwiki

Anodize means to coat a metal by either chemical or electrical means. The coating provides improved corrosion and wear resistance. The thickness of this coating depends upon the length of the treatment. This coating is often removed from the area to be welded and reapplied after welding. ^[1]

For example, to anodize aluminum, one would immerse the aluminum in a chemical bath and apply an electrical current to it, causing oxide to be produced from the resulting rust on the aluminum. This layer of oxide hardens the aluminum and makes it resistant to corrosion.^[2]

References

1. http://www.millerwelds.com/interests/instructors/pdf/Glossary.pdf
2. http://housewares.about.com/od/glossary/g/anodized.htm