Publication

Abstract : Cupro-Nickel and Aluminium alloy to their series, Al 5083 and 70Cu30Ni are the critical alloys in ship building mainly in piping section. Due to the reason of having a huge difference in their physical and chemical properties, obtaining a good bonding between them by welding is rather a tough job. The welding was conducted by giving waviness to the torch and allowing the molten pool of Cu-Ni to flow towards the Al 5083 and thereby joining them without melting the aluminium. The microstructure was studied by welding plain plates as well as Nickel coated plates. The microstructural study showed that there is a good bonding between the two alloys. The SEM imaging confirms the bonding of the two alloys at the welded region. The elemental composition of the weld joint was found by EDS analysis. The formation of intermetallics was confirmed by XRD analysis. Then the hardness at the weld joint was studied. The hardness value obtained from testing was promising and there with showing a good properties at the welded joint. The Ni coated welded alloys showed significant and improved results when comparing with the non-nickel plated metal plates. With the hardness value varying from the non Ni coated plates was found to be high compared to the hardness value of the Al and Cu-Ni alloy. But the further study showed that that hardness value adds much to the weld stability by the formation of good bonds between the alloys and that of the intermetallics formed. The impact tests conducted on the welded specimen shows good results with regards to the comparison with the impact strength of 70Cu30Ni and the energy absorbed by the welded specimen. The results showed that welding is possible between these alloys and the nickel coated alloys shows better results in strength and bonding than non- nickel coated alloys. This study also confirms that GTAW can be very effective in joining these dissimilar alloys.