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Q&As since 1989


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Colour anodising of Ti

I am looking for colour anodising of Ti. I know there are companies that're already doing that, but I want to know the underlying theory behind. I also want to know the properties of the anodised layer. Is there a certain website or literature where I can find out a bit more on the topic?

w.y.wong
- Hong Kong
2000

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A quick overview of the process involves passing a low density current through the titanium in an electrolyte. The current forms an oxide layer. This layer is thin and can be worn off or damaged in harsh environments. The oxide difracts light, and depending on the thickness, can appear yellow, gold, copper, blue, green, or violet. If the current density is too high, of if the electrolyte is too warm (above 85 F), the process breaks through the oxide and begins to etch. The resulting grey surface must be polished before another attempt to anodise is made.

Howard Bailey
- Flagstaff, AZ U.S.A.
2000