The study of high-speed MIG welding assisted by compound external magnetic fields for 6N01-T6 aluminum alloy

Abstract

The magnetic field generator was designed and assembled on the welding torch to produce perpendicular and parallel magnetic fields periodically in the arc to improve the weld formation of 6N01-T6 aluminum alloy at high-speed welding. The mechanism of this hybrid weld process was studied based on the analysis of arc behavior and bead formation at different excitation parameters. The microstructure, tensile strength and impact toughness of joints were tested and analyzed. Results showed that the compound external magnetic fields suppressed the weld-bead defects effectively and increased the welding speed from 0.75 m/min to 2.1 m/min. The stirring effect of compound external magnetic fields had the advantage of refining grains in the weld zone, which improved the tensile strength and impact toughness of joint at high-speed welding. It proved that the compound external magnetic fields assisted melt inert-gas welding was a high-speed and low-cost welding technology for aluminum alloy.