This disclosure provides a joining area and method between copper and stainless steel or titanium, as well as the permanent cathode obtained, where said joining area is made of a first zone of a copper-nickel (Cu--Ni) alloy, an intermediate zone with a mostly nickel alloy or pure nickel and a second zone made of a stainless steel-nickel alloy, which is the result of the participating materials being cast in an arc welding process, for example TIG, MIG or manual arc using electrodes of nickel as welding contributor between said materials and their space arrangement, that is to say, leaving a separation between the materials when performing the welding process, thus ensuring as follows: a) greater tensile strength, b) a substantial improvement of corrosion resistance of the joint welding, and c) improvement of conductibility, which can be improved still further by modifying the straight design of the conducting bar by providing it with the "horn"-type shape.