Copper-Aluminum Alloy

You don't weld copper-aluminum alloys like normal steel. The mixture of the two metals makes the structure sensitive, as brittle phases can easily form when heated. If you apply too much heat, you'll get cracks or the alloy will distort. You have to keep the heat input low and prepare the weld seam cleanly. A process with concentrated energy, like TIG or laser, is best suited. After welding, you should check the seam for cracks, because the electrical conductivity suffers if the structure has been damaged.