Induction brazing, like all other methods of brazing, requires selection of an appropriate brazing alloy and flux (if applicable).
Copper-based brazing metals are used extensively in the brazing of steel automobile components and are frequently induction brazed. Copper is chosen for its exceptional strength, ability to be press fit for ease of automation, and low cost. Melting temperatures are generally 1981ºF or greater. Silver-based brazing filler metals are used to braze both ferrous and non-ferrous alloys using induction brazing. Silver’s low brazing temperature conserves energy and limits metallurgical changes while resulting in low oxidation levels and formation of flux residues in brazed components. Some commonly used silver alloys for open-air brazing are BAg-24 and BAg-5.
Brazing preforms are used in induction brazing almost without exception, as these are convenient and highly appropriate for the rapid and localized heating key provided by the induction process. Preforms allow for pre-placement of brazing filler metal in an assembly for automated operations and guarantee a set amount of filler metal in every joint.
Brazing in a controlled atmosphere may eliminate the use of flux depending upon the atmosphere. Contact Bellman-Melcor for help choosing an alloy or for technical support with your induction brazing projects.