Now hold on there partner!!! Did you just say that you're trying to weld grade 2 Ti with a grade of stainless steel???
If you're talking about medical implantation, and implanting into an environment where the possibility of enhancing the corrosion potential where the two different metals are fused together without any control of dilution as a matter of concern, and not to mention the difference in noble #'s between whatever grade of stainless steel when mixed together with Ti - just makes a bad recipe that much closer to a recipe for disaster for the poor soul who will have the unfortunate luck of having this device fail inside of them... Are you really willing to risk such liability without considering at the very least these and mant more risk factor that MUST be considered when designing & manufacturing such critical device where the only ethical goal is to make it as safe as humanly possible???
I echo what Lawrence and Al suggest... Get in contact with some folks that are experts in this speciality, and digest as much reference data out there because if you do not, you will step on a landmine that will not only kill you in endless litigation if you even get it approved beforehand... It will almost certainly kill someone innocent, and as a consequence, cause more harm and litigation
to any one else associated with the defective product.
I would strongly suggest that you get in touch with TIMET as they are some of the best folks out there to advise you when it comes to successfully fusing together Grade 2 Ti, and I believe they know a thing or two when it comes to medical applications such as implanted devices. Titanium Industries may also be helpful as well as RTI international.
Las but not least, visit the corrosion doctor's web site as they will school you on the fundamentals regarding certain factors involving corrosion control because after all, the human body is at least ninety plus per cent water!!!!! CAPECHE??? Yes INDEED!!! OXIDATION DOES HAPPEN INSIDE ALL OF US ONE WAY OR ANOTHER!!!! :) :) :)
If you want me to paste the links - forget that!!! You're responsible to do the appropriate research so, Good Hunting!!! :) :) :) :) :)
Respectfully,
Henry