When considering the right material for your next transformer project, the place to start is with the budget that you have for your project. Copper is a traded commodity, which can cause variations in price due to the supply and demand. The price can also depend on the state of the mining market, which provides copper, and whether there are new mines coming online that will increase the supply to a specific geographical area. Aluminum is not a traded commodity, which means it can be up to 50% cheaper to use.
Other issues to consider include oxidation and size requirements. While both copper and aluminum can oxidize over time, aluminum will only continue to do so until all of the air exposed surfaces are covered. Copper corrodes less than aluminum does in salt water applications, so while some marine specifications allow for aluminum, copper is recommended. Aluminum wound coils are larger than an equivalent copper coil, therefore applications requiring very tight dimensions should use copper.
Aluminum is also an excellent heat storage material. While copper tends to cool more quickly, which can be a benefit in certain situations, aluminum can hold about 2.33 times more heat than copper. This means that aluminum transformers can handle additional overload and surges over their comparable copper transformers. This could be a benefit or a detriment, depending on your particular application.
Copper is more dense and has less conductivity, per pound, than aluminum. Aluminum can have up to twice the current carrying capacity. Copper has a slightly higher tensile strength and is more flexible than alum, so smaller transformers are generally wound with copper to avoid breaking or damaging the wire during winding.
Call the experts at Vortex Metals today for information and an estimate on aluminum and copper transformer products.