Transient simulation of pulsed gas metal arc melding (GMAW) processes and experimental validation

S. Rose - M. Schnick - M. Hertel - J. Zschetzsche - U. Füssel

Technische Universität Dresden, Institute of Surface and Manufacturing Technology, Joining Technology and Assembly, D-01062, Dresden, Germany

Abstract
Gas metal arc welding (GMAW) is one of the most important joining processes in today's industry. GMAW with pulsed current is a highly dynamic and unsteady welding process, in particular. In pulsed GMAW, the welding current, the temperatures, the geometry of the electrodes, the plasma composition (argon and vaporized metal) and the shielding gas flow change permanently. In this paper, transient simulations of pulsed GMAW processes are presented, which calculate the complex arc properties as a function of time-dependent boundary conditions of electrical current and the vaporization at the wire tip (mass flow and location). The calculated temperature and iron distribution inside the arc are in good agreement with spectroscopic measurements. The transient behaviour of current and voltage in phase space diagrams shows a very good agreement as well. Finally, a purpose-built particle image velocimetry (PIV) system is presented, which is able to measure the flow in welding arcs and to validate numerically the calculated flow characteristics continuously. Figs 8, Refs 9.