Effect of cadmium chloride flux in active flux TIG welding of mAgnesium Alloys

Abstract

The Cadmium Chloride flux increases the weld penetration evidently in the Alternating Current Tungsten inert gas (AC TIG) welding of magnesium alloy. In the present study, in order to investigate the effect of the CdCl2 active flux on the weld shape and arc voltage, bead-on-plate specimens are made on AZ31B magnesium alloy pre-placed with CdCl2 active flux by the AC TIG process. Weld pool cross-sections and the arc voltage are analyzed under different welding parameters, welding speed, weld current and arc length. The results showed that compared to the conventional AC-TIG, welding penetration and the weld depth/width with CdCl2 flux are both two times greater than that of without flux under optimal parameters. The voltage decreases with decreasing of travel speeds and arc length decreasing. Besides, the phenomenon of arc trailing in the EN period and arc contraction in the EP period were observed in AC TIG welding of magnesium alloy with CdCl2 flux. It found that the arc voltage increases with the increases of welding current, more energies are supplied for welding, resulting in the increases of arc voltage and weld penetration. © 2006 The Japan Institute of Metals.