Some more or less exotic materials will diffusion bond. I believe titanium is one. Diffusion bonds are accomplished at elevated temperatures in protective atmospheres or vacuum, but do not involve melting, brazing, soldering or adhesives. When clean surfaces are placed in close proximity, the component atoms will actually diffuse across the intervening gap and eventually bridge the gaps.

That being said, I somehow doubt that Mr. Searcy is actually using materials that can be bonded in this manner.