Details
Brazing is a technique to provide a solid joint between two (or sometimes several) dissimilar materials, mainly metal-based materials where the interface is produced by heating of an assembly while utilizing a filler metal. This filler metal compound has a liquidus temperature which is substantially below the solidus temperature. of the base materials (metals). For metals, brazing is usually accomplished by using a filler metal with a melting temperature above 450°C (840°F). This is in contrast to soldering, which employs a filler metal with a liquidus temperature below 450°C (840°F).
Like soldering, the molten filler metal is distributed by capillary action between the closely fitted surfaces of the two materials to be joined, which then forms a solid interface upon cooling. Due to the physical nature of the brazing process, it is imperative that the filler material has excellent wetting ability, meaning that the braze material must adhere evenly and uniformly over the entire surface via capillary action.