The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Hydrogen Absorption from Chemical Milling Titanium

Does anyone know where I can find information in regards to Hydrogen absorption during chemical milling of titanium?
We are trying to make sure that we will not get hydrogen embrittlement of the titanium after subjected to our solution. The solution is HF and HNO3 mixture.
I believe the concentrations are 7% HF and 11% HNO3. Any help would be appreciated.

Thanks, Joel

Joel Adams
aerospace forging - Worcester, Massachusetts
2003

Joel, you may want to check AMSC81769 for more information. Your solution chemistry appears right, assuming you monitor depletion and dissolved metal. The AMS specification will provide you with limits, but you probably have customer specification limits. What sort of testing have you done? Hydrogen levels must be monitored not only from the "pick-up" from chemical milling process, but the total hydrogen must not exceed the material specification levels additively from your "as-received" material condition and from your forging and chemical milling sourced hydrogen. What is your test method? Mass spectrography, or other? Before and after samples?

Douglas A. Hahn
- Ukiah, California, USA
2003