In gas metal arc welding (GMAW), a technology using pulsed currents has been employed to achieve the one-droplet-per-pulse (ODPP) metal transfer mode with the advantages of low average currents, a stable and controllable droplet generation, and reduced spatter. In this paper, a comprehensive model was developed to study the effects of different current profiles on the droplet formation, plasma generation, metal transfer, and weld pool dynamics in GMAW. Five types of welding currents were studied, including two constant currents and three wave form currents. In each type, the transient temperature and velocity distributions of the arc plasma and the molten metal, and the shapes of the droplet and the weld pool were calculated. The results showed that a higher current generates smaller droplets, higher droplet frequency, and higher electromagnetic force that becomes the dominant factor detaching the droplet from the electrode tip. The model has demonstrated that a stable ODPP metal transfer mode can be achieved by choosing a current with proper wave form for given welding conditions.
J. Hu and H. Tsai, "Effects of Current on Droplet Generation and Arc Plasma in Gas Metal Arc Welding," Journal of Applied Physics, American Institute of Physics (AIP), Jan 2006.
The definitive version is available at http://dx.doi.org/10.1063/1.2337261
Mechanical and Aerospace Engineering
General Motors Corporation
Keywords and Phrases
Arc Plasma; Droplet Generation; Gas Metal; Welding
Article - Journal
© 2006 American Institute of Physics (AIP), All rights reserved.