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Copper Welding Machines

The weldability of copper varies based on its purity, but there are many ways to weld the metal. Generally, the welding machine must be capable of producing high localized heat since copper has very high thermal conductivity. Even manual metal arc welding machines can be used to weld copper, though the weld quality is lower than that obtained with other processes.

Brazing
- Brazing machines can be used to fuse copper pieces together. Brazing is the process of joining two metal pieces by fusing them with a filler metal that has a lower melting point than the base metal's melting point but higher than 450 degrees Celsius. Brazing machines are available for both induction and resistance brazing. Induction brazing uses an electric current and so does not require the machine to make contact with the workpiece; resistance brazing requires contact between the machine and workpiece.
Oxy-acetylene Welding
- Oxy-acetylene welding tools can be used to either braze or weld copper or copper alloys, though it may result in a lower weld quality in some coppers. Oxygen can collect at the grain boundaries of some copper, causing the heated area to become brittle. Copper welds should be struck with a hammer, or peened, to strengthen the weld by reducing the weld's grain size and releasing stresses in the metal.
Gas Tungsten Arc Welding
- Copper pieces up to 16mm can be welded using a gas tungsten arc welding machine and appropriate filler metal with a composition similar to that of the base metal. Argon shielding gas is best for welds on metal up to 1.6mm thick; helium-argon mixture is best for sections thicker than 1.6mm.
Gas Metal Arc Welding
- Copper can be welded using a gas metal arc welding machine with high amperage capabilities. GMAW machines can use different types of shielding gases depending on the thickness of the copper section to be welded -- argon for 6mm and under or helium-argon mixture for thicker sections. Electrode diameters, preheat temperatures and voltage rates should also increase with the thickness of the copper to be welded.

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