A Study of Pulsed Arc Welding Applied to Aerospace Alloys.

Initially it was thought that pulsing the GMA welding arc might preclude the need for stabilizing additions to the shielding gas, and that controlled one-drop-per-pulse metal transfer could be used to reduce contamination or alloy depletion that occurs with a spray multiple-droplet transfer welding arc. It was determined that the use of pulse arc welding did not preclude the need for arc stabilizers such as oxygen andor carbon dioxide. Furthermore, it was shown that with a modified Vickers power supply, one-drop-per-pulse transfer could be achieved only under a very limited range of conditions, and that more suitable welding performance resulted from multiple-drop-per-pulse metal transfer. The results of mechanical and metallurgical tests showed no significant general improvements in weld quality that could be traced to pulse welding variables. Further, pulsed GMA welds were of lower quality in terms of soundness, strength, and toughness than the corresponding GTA welds.