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Titanium Anodizing

My name is Andrew Hughes I've worked with chemical IAW Chromic and Sulfuric Anodizing. To my knowledge the Titanium market is monopolized by a company called Tiodize in California. I'm trying to find a good way to etch the titanium I've found ammonium bifluoride to be very nasty. For my actual anodizing tank I've read around and heard 80% phosphoric 10% sulfuric and 10% Di Water. My brother is an electrician but we're trying to figure out the proper grounding techniques. Should the Cathode be attached to a ground bar? I don't understand how the Anode wouldn't shock the hell out of someone. I'm guessing this has something to do with the anode to cathode ratio. If you could give me a brief description in how to not kill myself I'd appreciate it.

Thanks

Andrew Hughes
student - Valrico, Florida
May 14, 2009

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May 14, 2009

Hi, Andrew. We have dozens of threads about titanium anodizing. I wish you had tacked your question onto one of them because there is so much to explain that I hate to start over again :-)

There are two very different kinds of generic titanium anodizing, more fully explained in the on-line library article "Why Coat Titanium?". The first type is alkaline anodizing, which is a grayish engineering finish for the purpose of corrosion resistance, resistance to rocket fuel, reducing galling, etc. This is done in accord with AMS 2488. While Tiodize is a powerful player in this market, they do have competition.

The other general type of anodizing is "neutral" or "acid" or "color" anodizing. This applies a very thin transparent layer of oxide which, due to diffraction effects, appears to be of various colors depending on the thickness applied. Since it is a resistive coating, the applied voltage determines the thickness and consequently the color. The usual electrolytes are coca-cola, or a thin solution of TSP, or very mild acids. I am not familiar with using 80 percent phosphoric acid, but there are licensable proprietary technologies.

Part of the safety issue involves using a proper isolation transformer, so that there is no voltage between ground and either the anode or the cathode, but I cannot advise via an internet posting all of the necessary protocols for a safe operation. The isolation transformer must work, and still offers no protection if you touch both anode and cathode. Most plating shops won't do processes that requires high voltages because of the safety issues. For example, one fabulous metal finishing process, anodizing of zinc, has never gotten traction because plating shops will not install a process that uses hundreds of volts. Good luck.

Regards,

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

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2000

I would appreciate if you could guide with information as to achieve titanium coloration through anodizing process for achieving consistency in coloration on titanium metal namely for decorative front.

Equipment required and process involved.

Thanking you,

M.Shah
- Mumbai, Maharashtra, India