Induction brazing

Induction brazing is when two or more materials are joined together by a filler metal that has a lower melting point than the base materials using induction heating. In induction heating, usually ferrous materials are heated rapidly from the electromagnetic field that is created by the alternating current from an induction coil.

Benefits

• Brazing provides design and manufacturing engineers an opportunity to join simple as well as complex designs.
• The process is fast enabling a quick throughput of parts.
• Allows brazing of very defined and selective areas

Application & materials

Induction brazing is the process by which metal components are joined using a dissimilar lower melting point material, utilising induction heating.

Brazing can also be accomplished by using furnaces of different designs which include batch as well as continuous furnaces. There are many types of brazing, including:

• Torch brazing
• Active metal brazing
• Aluminium vacuum brazing
• Brazing under controlled atmosphere
• Honeycomb brazing
• Continuous/mesh belt brazing
• Reducing atmosphere brazing
• Repair/restorative brazing
• Vacuum brazing

Induction brazing can only be applied when one part is ferro-magnetic.

The materials being joined dictate the type of atmosphere in which the assembly is heated to join its components. In addition to vacuum, protective or reactive atmospheres include hydrogen, nitrogen, a blend of hydrogen and other inert gases, exothermic and endothermic gas, as well as argon, and helium.

Certain dissimilar materials are difficult to join. For example, ceramic to metals and reactive metals such as magnesium and beryllium.

Process details

A medium-frequency or high-frequency alternating current is passed through an induction coil and creates a magnetic field around the coil. When a conducting material, such as steel, is held in the centre of the coil, the magnetic field causes a current to flow in the surface of the steel, which heats it up. Joints are created using a lower melting point braze filler which is melted by the rapid heating of the area to which it has been applied.