Inert Gas Welded Magnesium Alloy Research Articles

Investigations on Tungsten Inert Gas Welded Magnesium Alloy

Generally, magnesium alloys show interesting technological characteristics, which make them valuable for many industrial applications. Good mechanical properties, creep resistance and good castability, recyclability are only some of the most important properties remarkable for their employment in different areas. Generally, at industrial level welding technologies, like Tungsten Inert Gas technique, are used to eliminate and/or to repair the casting defects. In the present paper some details on their microstructural behaviour and mechanical performances on welded WE43 magnesium alloy are evaluated and reported. The obtained results have demonstrated that welding do not decrease the mechanical performance of the material and the heat affected zone cannot compromise the overall behaviour of the welded samples. In most of cases, the material’s failure takes place nearly the welding defects.

Influence of Filler Rod Composition on the Strength of Tungsten Inert Gas Welded Magnesium Alloy Joint

The influence of filler rod composition on the strength of Tungsten Inert Gas (TIG) welded magnesium alloy joint was investigated. Samples were rolled AZ31 (Mg-3Al-1Zn) magnesium alloy as base metal and drawn AZ31, AZ61 and AZ91 magnesium alloys as filler rod. The results show that all fracture points were fusion zone (FZ), and each joint efficiency (=joint strength/ base metal strength) was 70.7%, 80.0% and 73.1% when using AZ31, AZ61 and AZ91 filler rod. When using AZ91 filler rod, 0.2% proof stress was the highest but the elongation was the lowest among the three conditions, and joint efficiency was lower than that when using AZ61 filler rod. It is thought that welded joint was strengthened by solute strengthening, but excess addition of aluminum facilitated crystallization of Mg17Al12 phase. This is the reason why elongation and joint efficiency when using AZ91 filler rod decreased. In conclusion, it is effective to use filler rod which does not excess solid solubility limit.