Structure and Mechanical Properties of Pulsed-GMA Welded Al-Li Alloy

摘要

Weldability studies on 13.7mm thick plates of experimental alloy Al-4.45 percentCu-1.18 percentLi-0.48Mg-0.4Ag-0.14Zr were carried out using Pulsed-Gas Metal Arc Welding (P-GMAW) and 2319 filler wire. Metal droplet transfer frequency was varied maintaining one droplet detachment per pulse (ODPP) condition and with mean current was kept constant. Bead-onplate as well as multipass butt-welds were made and investigated through microhardness measurements, metallography and tensile tests. Some butt-welds were made by laser welding as well. P-GMAW yielded reasonably good tensile properties in the welded joint comparable to the laser welded joints. At a given mean current, increase in pulse frequency resulted in coarsening of microstructure and reduction in strength.