Flexible Waveform Interpulse TIG Welding for Titanium Alloy

Abstract

：Based on the self-developed SiC MOSFET interpulse welding power supply system, a novel flexible waveform interpulse welding technology is proposed. The SiC MOSFET is used as the inverter power device, which improves the inverter frequency and the dynamic response of the power supply. The interpulse welding power supply enhances the control effect of high-frequency arc to reach high stability in output of the regular and flexible current waveform of the interpulse at 20 kHz. The method is applied to the welding of titanium alloy TC4. Compared with the conventional pulsed TIG, the arc radial dimension of the interpulse TIG is reduced, and the grains in the fusion zone and HAZ of the weld are significantly refined. The average grain size in the fusion zone is decreased by 71%.