I am using resistance welding T2 and 2MM thick copper pillars. There are many kinds of electrode materials now. Always sticking to electrodes. There's no better way.
Chromium plating / nickel reduces adhesion, but conductivity decreases.
The 2MM thickness is relatively thin, large diameter cylinders, copper stud welding by flame preheating before welding and the recommendations (for reference)
If it is necessary to fine tune the welding current, the current size determines the fusion and adhesion. It has nothing to do with the material of the welding electrode.
