I like anodized titanium.
Titanium anodizing is an electrolytic finishing process that creates varying thicknesses of a titanium oxide layer on the metal surface. The titanium item forms the anode (positive electrode) of an electrolytic cell, hence the name “anodize.”
Anodizing titanium has been around for almost a century. It was first used in 1923 to protect British seaplane parts from salt-water corrosion. Aerospace companies continue to use anodizing processes today to protect metals from the effects of aging, wear and corrosion.
There are three types of anodizing. The first is a high-temperature process. I used to etch titanium wire with molten sodium nitride into amazingly sharp points. I would find little splotches of concentric color on portions of the metal.
Frank goes into more technical detail on the anodization process than I did in this related article.
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