Brazing and Soldering
August 26th, 2006Brazing and soldering can both be made more efficient by applying induction heating. Induction heating process can produce the cleanest, most reliable joints possible for your part. Induction heating systems can be easily integrated into your line with continuous automatic feeds and may be designed to provide heat at multiple locations simultaneously.
Brazing is a joining process whereby a non-ferrous filler metal and an alloy are heated to melting temperature (above 450°C; 800°F) and distributed between two or more close-fitting parts by capillary action. At its liquid temperature, the molten filler metal interacts with a thin layer of the base metal, cooling to form an exceptionally strong, sealed joint due to grain structure interaction. The brazed joint becomes a sandwich of different layers, each metallurgically linked to each other. Common brazements are about 1/3 as strong as the materials they join, because the metals partially dissolve each other at the interface, and usually the grain structure and joint alloy is uncontrolled. To create high-strength brazes, sometimes a brazement can be annealed, or cooled at a controlled rate, so that the joint’s grain structure and alloying is controlled.
Soldering is a method of joining metal parts using an alloy of low melting point (solder) below 450 °C (800 °F). Heat is applied to the metal parts, and the alloy metal is pressed against the joint, melts, and is drawn into the joint by capillary action and around the materials to be joined by ‘wetting action’. After the metal cools, the resulting joints are not as strong as the base metal, but have adequate strength, electrical conductivity, and water-tightness for many uses. Soldering is an ancient technique that has been used practically as long as humans have been making articles out of metal.