Effect of Continuous and Pulsed Current Tungsten Inert Gas Welding of Cast Al–Mg–Sc Alloy

Abstract

The vacuum induction melted cast aluminum–magnesium–scandium (Al–Mg–Sc) alloy was subjected to continuous and pulsed current tungsten inert gas welding. The comparative study between the two joining methods was done using mechanical and metallurgical characterization techniques. The microstructure of TIG welding was coarser than that of the P-TIG welding process. The tensile failures were observed at the weld in the case of P-TIG welding and at the base metal for TIG welding. The TIG welded joints were stronger than the P-TIG welded joints as well as the cast base metal. The loss of hardness was more in P-TIG welding than the TIG welding process compared to the base metal hardness values. The evaporative losses of magnesium are more or less the same in both the welding processes. TIG welding of Cast Al–Mg–Sc alloy plate is more reliable than P-TIG welding.