Definition of brazing

i. Joining metals by flowing a thin layer (capillary thickness) of nonferrous filler metal into the space between them. Bonding results from the intimate contact produced by the dissolution of a small amount of base metal in the molten filler metal, without fusion of the base metal. Sometimes the filler metal is put in place as a thin solid sheet or as a clad layer, and the composite is heated as in furnace brazing.

Ref: ASM, 1

ii. In joining metals, the term 'brazing' is used where the temperature exceeds some arbitrary value, such as 800 degrees F (427 degrees C); the term 'soldering' is used for temperatures lower than the arbitrary value.

Ref: ASM, 1