What is Brazing?
Knowledge of the ancient art of brazing is continuously being supplemented by an ever increasing amount of technical information about metals and their behavior, so that today brazing must be considered both an art and science. This edition of the Brazing Handbook (formerly the Brazing Manual) includes the fundamental concepts of brazing and incorporates the many advances made since the manual was first published.
The American Welding Society defines brazing as "a group of welding processes that produce coalescence of materials by heating them to the brazing temperature in the presence of a filler metal having liquids above 840oF (450oC) and below the solidus of the base metal. The filler metal is distributed between the closely fiyyed faying surfaces of the joint by capillary action".
Brazing then must meet each of the three criteria:
- The parts must be joined without melting the base metals
- The filler metal must have a liquidus temperature above 840oF (450oC)
- The filler metal must wet the case metal surfaces and be drawn into or held in the joint by capillary action.