Technique for welding copper to aluminium

Aluminum tubes are increasingly being used for pipes in refrigerationand heating and air conditioning applications. These are often used incombination with copper pipes.
The quality and cost-beneficial linking of these materials is a major challenge. These heterogeneous connections are being implemented mostly throughsoldering and brasing process', which is well known that this isrelatively labor intensive and an expensive technologies.

Recently, the Qingdao Ocean University in China developed new resistancewelding materials for welding. The welding method requires noexpensive equipment or skilled welders and is used for welding pipeswith a diameter of 3 to 20 mm, with wall thicknesses of 0.5 to 1.6 mm.

Thewelding tubes are bevelled and then placed into a specific welding position in a specially developed machine. Via electrical contacts, a flow is sent through the tubes.

As a result of the heat, a connection is made and inter-metallicphases are formed. The formed connections are air- and leak-proof andcan resist internal pressure.

Source: techniline.sirris.beAdded: 25 August 2009