Titanium and Niobium cannot be soldered, so I am told.
So, short of Fusion Welding, Jewelers 2-part Epoxy seems to be the only alternative for bonding these elements.
There are 2 concerns regarding Epoxy Resin.
First, and foremost, is the fact that Epoxy Resin is an allergen causing agent in itself. Although not everyone suffers from Allergic Contact Dermatitis/Eczema, those of us who do, seem to be prone to react to a specified list of items. Epoxy Resin is one of them.
This means, in jewelry design, it is important that no Epoxy touch the skin. Although it is acceptable under governmental code (even in California), to label a pierced earring “hypo-allergenic” if at least, the post itself contains no allergen causing agents, the fact is, it’s not just the post that comes into “contact” with our skin.
Second, it is difficult to adhere Titanium and Niobium with Epoxy Resin. But I have found that attention to certain details seems to be the answer for success.
* The larger the two surfaces to be bonded, the more secure the bond.
* Etch the two surfaces well. Epoxy needs nooks and crannies to create a place to bond. I usually do this with needle files, in a cross hatch fashion. Filing in both directions creates an etching effect, as opposed to filing in one direction which creates a buffed effect.
* Remove all dirt, debre, and skin oils from the surfaces to be adhered. Rubbing alcohol works fine for this.
* 2-part Epoxies contain Resin, and Hardener. It’s important to use equal amounts of each. I use a paper plate and squeeze equal sized drops of each, next to one and other. Give it a moment to make sure that the two liquids (which are different in consistency to each other) are actually equal. Then I mix well with a toothpick, and apply evenly to one of the surfaces.
* I then have 5 minutes to set the second surface, press into place, and remove any excess (with a dampened cloth.
* I usually let this cure under a lamp for 12 hours. Then test the adhesion by trying to remove the two components from one and other. If it doesn’t come apart, I consider it a success. If it does come apart, it usually means that I didn’t etch the surfaces well enough.
Follow up care to the finished piece should include the following considerations. Don’t soak the piece for any length of time. Don’t use harsh chemicals on the piece. Both of these actions can loosen the epoxy.