The authoritative public forum
  for Metal Finishing since 1989
-----

High temperature hydrogen barrier for nitinol or titanium

I am looking for a coating (or?) to prevent hydrogen embrittlement of the titanium in nitinol. The part will be subjected to around 1000 deg C for 10 - 15 minutes in forming gas (10% hydrogen/90% nitrogen) and I want to prevent damage to the part.

Matt Patterson
engineer - Lomita, California, USA
2005

---

It was found some years ago that hydrogen embrittlement could be alleviated by ion implanting the surface with platinum. The embrittlement comes from atomic hydrogen diffusing into the surface, not molecular hydrogen. Platinum acts as a catalyst, accelerating the recombination of atomic hydrogen into molecular hydrogen. Implantation works well because the whole surface gets covered, and the amount of platinum needed is negligible. If you try it with a coating, the coating can't have any pinholes. Either way you'll have problems if the parts have internal surfaces.

Jim Treglio - scwineryreview.com
PVD Consultant & Wine Lover - San Diego,
California
2005

If you are using Platinum ion implantation to resist hydrogen embrittlement for nitinol, then does it help in reducing other types of corrosion e.g. pitting, fatigue corrosion, stress corrosion cracking. Does it affect nitinol's strength? Again when the nitinol is under high tensile stresses, will the implanted ion be effective over the whole surface?

M.S. Alam
The University of Western Ontario - London, ON, Canada
2006