Evaluation of Arc Stability in Double-Wire DP-GMAW of Aluminum Alloy Based on U-I Graph

Abstract

Severe arc interference in double-wire double pulsed gas metal arc welding (DP-GMAW) can affect the stability of the welding process. In this study, voltage and current waveforms during double-wire DP-GMAW of aluminum (Al) alloy in the 0 deg and 180 deg phase shift modes were recorded. The relationship between arc voltage and welding current was investigated through the output voltage-current (U-I) graph. In addition, arc load characteristics and variation of voltage and current during the DP switching process were analyzed. The arc behavior was recorded throughout the welding process using a high-speed photography system, and the relationship between the U-I graph characteristics and arc stability was further investigated. The experimental results demonstrate that the arc is more stable in the 180 deg phase shift mode. In both phases, the leading arc impedance is more capacitive, and the trailing arc impedance is more resistive.