In addition to brazing we also perform diffusion bonding. This particular bonding process is commonly used on accelerators and mini-coolers where braze joints and braze fillets can shift the resonant frequency of a cavity or add a very thin thermal shunt layer which is avoided in diffusion bonding.
This joining technique bonds two metals together without the use of alloy. Two metals are pressed together with extreme force and at high temperatures. Metal atoms diffuse into the adjacent material forming what is called a Diffusion Bond. This technique is commonly performed on Copper and Titanium components and requires very specific conditions such as temperature, pressure, time at temperature, surface finish, and surface flatness.