Effect of Sc on the Wettability of ER5356 Welding Wires and the Porosity of Deposited Metal

In this study, Al-Mg and Al-Mg-Sc ER5356 welding wires were adopted, and the effects of the Sc element on the wetting behavior of the molten metal and the porosity of the deposited metal were investigated. Al-Mg-Sc and Al-Mg welding wires exhibit wetting angles of 17.2 and 12.4°, respectively, and their porosities of deposited metal were 0.885 and 0.454%, respectively. Adding the Sc element to ER5356 welding wires reduced the surface tension and then increased the pore difference pressure, wettability, and spreadability of the molten pool, which is beneficial for pore overflow. Besides, adding Sc elements could increase the molten droplet size and the metallic vapor recoil for the ER5356 wire and then stabilize droplet transfer.