Metal finishing Q&As since 1989

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Please Help with Anodizing of Titanium Difficulties

I would like any feedback we could get on the processes involved in anodizing titanium we are still not achieving an accurate or consistent result. Should we be using a titanium wire as the anode holding the piece into the bath to avoid any deposition onto the cathode.

I am a jewelry manufacturer in Australia and I realize from reading many of your past threads/topics a lot of your members have considerable knowledge in the plating of titanium. We are trying to get consistent results in various colours anodizing wedding rings.

We have a variable 100 volt rectifier x 5 amps which we do not have control over. The solution we are using is 10%water, 10% sulfuric acid and 80% phosphoric acid (we have had slightly better results using a weaker solution). The cathode is platinized titanium mesh and the anode (ring)is being connected by 3 mm copper wire.

Unfortunately when we perform the process the amperage increases much quicker than the voltage the maximum voltage I can produce before the D.C overload cuts in is about 20 v, and although we may reach 20 v the anodizing is only a faint yellow. Do we need to be able to adjust our amperage down (this is what I think is the major problem I would just like some more feedback), is there a particular cathode to anode ratio we should work to. Any assistance helping us to get an accurate and consist setup would be greatly appreciated. Regards

Aaron Jackson
- Australia
2000

Ed. note: Sorry there's been no response, Aaron. I guess this subject was covered too many times and people got winded. Put 'titanium anodizing' in the search engine and you'll see dozens of answered inquiries, including your own thread/topic 1762. Good luck.