Abstract
The arc welding method, hereinafter referred as Switching TIG-MIG Welding Method, was carried out in the welding of thick plates of copper without preheating. This method is characterized by preventing the arc interaction between TIG and MIG electrodes by switching alternately the welding current to each electrodes. Furthermore, in this method, the polarity of the tungsten e!ectrodc of TIG is negative to eliminate its consumption and the polarity of the feeding wire of MIG is positive to increase its melting rate.
In the welding for bead-on-plate runs with 10 mm thick copper plates, the deep penetration can be achieved by bringing each electrode closely and by increasing the TIG current in keeping the MIG current constant. Due to preheating by the leading TIG arc, the penetration in copper base metal incr as.s mor.: than a conv.ntional MIG.
In those experiments, 10 mm thick copper plates are welded in one pass without any preheating. Therefore, this welding method was found effective in the welding of copper plates.
