Metal finishing Q&As since 1989

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Chemical pretreatment of titanium alloys before anodizing

2003

Good morning everybody!

I'm searching for a convenient way to chemically degrease and activate titanium alloys as a pretreatment before anodizing. At the moment I'm using a proprietary alkaline degreasing agent at 65°C and for activation I immerse the titanium parts for 4 minutes in a mixture of 32% HNO3 and 0,5% HF. To be honest, the end results are inferior so far, which I ascribe to a lacking pretreatment. I'd appreciate it very much if you could help me out with your expertise, since I'm new to the trade of anodizing.

Thanks in advance,

Robert Sauerbrey
TU Graz - Graz, Austria

A common ratio of nitric to HF is 14. A 2%HF will give a much better result than the 0.5% that you are using.

James Watts
- Navarre, Florida
2003

adv.