Influence the Filler Metal Containing Zirconium on the Weld Metal Porosity of the MIG Welded Aluminum Alloy 5083

Abstract

The aluminum alloy series 5083 has high corrosion resistance and high specific strength properties; hence, it is widely used for ship structures, marine components, cryogenics of LNG tanks, and unfired pressure vessels. This study was undertaken to investigate the effect of zirconium on weld metal porosity and hardness of MIG welded aluminum Alloy 5083. Zirconium is one of the alloying elements that are mostly used for grain refining in the aluminum casting process. Zirconium element was previously added in the electrode wire as a filler metal. The experiments were carried out by MIG welding for several aluminum alloy plates to produce the full penetration weldments. Two different filler wires used in the welding: One is containing zirconium, and another is no containing zirconium. The grain size of weld microstructures was measured using a Linear Intercept Method (ASTM E 112), and the hardness measurement is conducted using micro-Vickers along the cross section of AA-5083 weldment. Results showed that the grain size of AA-5083 weldment using the filler metal containing zirconium was considerably finer size than that of using the filler metal without zirconium. Moreover, the hardness of AA-5083 weldment using the filler metal containing zirconium is generally higher than that of using the filler metal without zirconium.