A comparative investigation on weld metal properties of similar and dissimilar TIG welded joints on Al-Mg alloys

Similar and dissimilar welding of aluminum-magnesium alloy plates 5083 and 5010 was performed based on their marine application due to the excellent corrosion resistance, ability to retain strength post welding, and improved strength when operated at sub-zero temperature. TIG welding was employed for joining the plates using ER 5356 as the filler alloy due to its excellent corrosion resistance to saltwater and high concentration of Al-Mg matrix which enhances the intermetallic bond thereby increasing its strength. Two sets of welding, one consisting of dissimilar weld with 5010 and 5083 and the second with similar weld between two 5083 plates were considered for the research. Mechanical tests like Tensile, Bend, Hardness, and corrosion with microstructural analysis were performed on all the weld samples and it was observed that samples of similar welds had marginally higher tensile values than the samples of dissimilar welds. The microstructure analysis displayed that the weld and HAZ regions of dissimilar welds were dense and isolated while the HAZ of similar welds had minor amounts of Cu which inhibits grain growth thereby effecting the strength.