Heat Sources

Brazing is such a process in which the source of heat is very important. It is done at a temperature above the melting point of the brazing filler metals but below the melting point of the base metals. For different brazing processes the source of heat is different. Let's take a look at the different sources of heat in brazing.

Torch Brazing
Torches are the primary sources of heat in torch brazing. Torch brazing is usually preferred for low-volume applications and small assemblies.




Furnace Brazing
In furnace brazing, furnace is the main source of heating. It does not required a competent operator, and is often used to braze several assemblies at the same time. The filler material is pre placed. However the furnaces require long time for start up and cool down. So once started they run for several months at the stretch.




Dip Brazing
Dip brazing is primarily used for aluminum brazing. The primary source of heating is a molten chemical or metal bath. The parts to be joined are dipped in the molten flux bath, which doubles as the heating agent. This process is used for small wires, sheets and other components that are small enough to be immersed. Heat is produced by the resistance of the parts to the current.



Induction Brazing
Induction brazing is one of the important brazing processes, which gets the heat from the induction coils. This process has the advantages of speed, accuracy and consistency. They consistently and quickly provide accurate amount of heat to a small area to be joined. Each part is identically positioned in the induction coil and the filler alloys are carefully regulated.




Vacuum Brazing
Vacuum brazing is typically used for brazing the complex assemblies. It is a joining technique which is preferred because it is extremely clean and superior and produces flux-free braze joints of high strength and integrity. The heat source is a vacuum chamber vessel, which is heated to a temperature as high as 2400 °C. Vacuum furnaces also work at lower temperatures which are economical. The basic advantage of such furnaces is that temperature uniformity can be maintained on the object when heating in a vacuum.