Microstructure changes of the tungsten insert in CuCrZr compound electrode during resistance spot welding of galvanized sheets

摘要

The microstructures of the compound electrodes with tungsten insert were characterized using scanning electron microscopy. Resistance spot welding compound electrodes used in this study were prepared from precipitation-strengthened and cold-formed domed flat electrodes consisting of Cu-0.7Cr-0.2Zr alloy and tungsten insert. Detailed study of the microstructure of pure compound electrode, compound electrode after 800 cycles of mechanical compression load at room temperature and after 800 welds of the same sheets with protective coating were investigated using scanning electron microscope.