Twisting Electrodes Improve Tip Life and Weld Quality on Resistance Spot Welded Aluminum Sheet

A new electrode holder designed for resistance spot welding of aluminum twists the electrode while it contacts the workpiece. The limited rotation grinds the electrode tip into the surface of the workpiece, abrading it and obtaining good electrical contact. The improved electrical contact results in less heat generation at the tip/workpiece interface, which leads to longer tip life and more consistent welds. Test results show that tip life increases nearly 500 percent when using a twisting electrode holder. In addition, weld quality is improved and more consistent welds are produced than with standard spot welding practice. By using these new electrode holders, automobile manufacturers will decrease the downtime associated with replacing electrode tips and reduce the number of assemblies that have to be torn apart for quality control inspection.