Patent ID: 9676065
Date: 2017-06-13
CPC Classifications: B23K

Claim:
1. A method of resistance spot welding aluminum-to-aluminum and steel-to-steel using a single resistance spot welding gun apparatus, the method comprising: providing a spot welding gun apparatus that carries a pair of opposed electrodes, each of the pair of opposed electrodes having a body and a crowned weld face at one end of the body, the crowned weld face of each electrode having a spherical radius of curvature between 20 mm and 40 mm and further comprising a plurality of concentrically arranged circular ridges that project outwards away from the weld face; forming a series of aluminum to aluminum welds, wherein formation of each of the aluminum to aluminum welds comprises pressing the opposed electrodes of the spot welding gun apparatus against opposite sides of an assembly of two or more overlapping aluminum panels and exchanging current between the opposed electrodes; forming a series of steel to steel welds after forming the series of aluminum to aluminum welds, wherein formation of each of the steel to steel welds comprises pressing the opposed electrodes of the spot welding gun apparatus against opposite sides of an assembly of two or more overlapping steel panels and exchanging current between the opposed electrodes; and dressing each of the electrodes after forming the series of steel to steel welds and before forming another series of aluminum to aluminum welds, wherein, for each of the opposed electrodes, the dressing includes restoring the spherical radius of curvature of the weld face and the plurality of concentrically arranged circular ridges on the weld face, and removing contamination from the weld face that has accumulated as a result of forming the series of aluminum to aluminum welds and the series of steel to steel welds.