Wrought Copper Alloy Recrystallization

If you want to make copper alloys soft and formable again after cold forming or welding, you do it by recrystallization. New, undeformed grains form in the structure, replacing the old, hardened structure. It's important that you heat the material evenly and not too hot, otherwise the grains grow too coarse and the material becomes brittle. Keep the temperature just high enough and for just long enough to achieve the desired softness, then let it cool slowly. Too hot or too long is the most common mistake, so better work controlled and, if in doubt, feel or test it.