For information - titanium alloys can be brazed, in a manner. There are basically two jointing alloy options - a low temperature aluminium-magnesium based alloy system range which is a real dissimilar 'brazing' system; and a higher temperature nickel-titanium system range, with compositions all the way between the two parent elements whic is closer to a dissimilar wleding fille rin a lot of cases.

Titanium Brazing Inc, of Ohio do a range of filler metals, powders and foils for the purpose. I'm sure a number of other companies will, but that's justy of the top of my head.