UNDERSTANDING THE MECHANISMS OF ALUMINUM BRAZING

Understanding the mechanisms by which brazing occurs is one of the keys to improving methods for brazing aluminum. The mechanism generally differs for each aluminum brazing method but always involves opening pathways through the oxide films for the flow of filler metal. The ways in which this is accomplished are discussed for conventional dip, torch, and furnace brazing with salt fluxes and for some newer fluxless brazing methods such as vacuum brazing employing metal activators, halide vapors, or prolonged heating at elevated temperatures.