Welding of Copper and Copper Alloys
Welding of copper and its alloys is a very popular and important process in the fabrication of many products today. Copper is well known for its electrical and thermal conductivity properties, as well as its ductility, and as such is used in a range of industrial sectors including electrical, electronic and automotive manufacturing. Copper alloys also exhibit excellent mechanical properties, making them suitable for a wide range of applications. Welding of copper and copper alloys enables the uniform assembly of components into products which can be used for a range of applications.
When welding copper, the welding process selected must be appropriate for the specific material. Copper has a low melting point, at around 1066ºC (1950°F), and its alloys have slightly higher melting points. This means that a number of different welding processes are available for welding copper, including gas metal arc (GMAW) welding and gas tungsten arc (GTAW) welding. Each of these welding processes offers specific benefits; for instance, GMAW welding provides faster welding speeds than GTAW welding and is also more economical.
GMAW welding process is popular for welding copper and its alloys, but GTAW welding is also successful. Both of these welding processes require the appropriate filler materials. Low melting point filler materials must be used, such as copper alloys, silver brazing alloys, aluminium bronze and brass. The welding power supply and tools used must be appropriate for the chosen filler material and the type of welding process to be conducted.
Special care must be taken when welding copper and its alloys; the welding process can cause a number of problems if it is not conducted correctly. For instance, copper has a very high thermal conductivity and this can cause heat to be transferred away from the welding area very quickly. This means that preheating of the copper parts must be incorporated into the process to reduce the rate of cooling during welding and to ensure that temperatures remain consistent during welding. An inert shielding gas is also required to protect the weld from atmosphere contamination.
In addition, the surface of the copper and copper alloy parts need to be cleaned to a high standard before welding. The parts should be free from any dirt, grease or oil and any existing deposits of copper oxide should be removed. The parts should also be in good mechanical condition to ensure a sound weld. This will also ensure that any weld distortions caused by heat build-up during welding are kept to a minimum.
Welding of copper and copper alloys is an important process for the fabrication of many products today. Careful consideration must be taken when selecting the most appropriate welding process and filler materials and when undertaking the welding task. If suitable precautions and processes are undertaken, it is possible to produce high quality welds that are suitable for the application intended.
