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Titanium anodic coating

2005

Two rods of Ti-6Al-4V were anodic coated. One rod became gray while the second has blue areas and gray areas.

Are you familiar with gray anodic coating on titanium alloy (we expected the color to be violet-blue)?

What are the differences between coatings having different colors?

Shai Sabatello
IAI - Israel

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Was this acid anodizing or mil-spec alkaline anodizing. What was the voltage?

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005

It was sulfuric acid anodizing, at 20-25V and 0.2-0.4A.

Shai Sabatello
- Israel
2005

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If you were looking for a violet-blue color, your probably talking about acid anodizing of titanium, something like the ISO 8080 spec.

The voltage controls the different colors by controlling the thickness of the coating, the colors are created by the bending of light inside the coating in a manner similar to a prism.

If you are hitting grey colors with hints of blue (but no purple or brown) your voltage is probably too high (25-30 range maybe?) and you may want to try turning it down to 19 volts or so.

Good luck,

Jim Gorsich
Compton, California, USA
2005

adv.