brazing (B)

What sets brazing, braze welding and soldering apart from welding is that welding is the only process in which the base metals are heated to their melting point.
Brazing relies on the molten filler metal's adhering to the base metal. It is more like gluing than welding. Brazing temperatures ranging between 1200 and 1400 degrees F, so it is a high-temperature process compared to soldering, but a cool-temperature process compared welding.
Flux is used in order to ensure adhesion between base metal and filler metal.
It also has the effect of dissolving and removing unwanted oxides.
Wetting is when the liquid filler metal, aided by the flux, spreads out in a thin layer over the base metal and becomes ready to flow on or into a joint.
Brazing filler metals are named "B" followed by the element symbol from the periodic table, followed by a dash and then a number indicating what percent of the filler metal is alloy.  For example, BAg-4 indicates a filler metal that is 4 percent silver.

Brazing may be a better alternative than welding for metals with sensitivity to high temperatures.