Investigation of Intermetallic Compound Formation in Dissimilar Metal Welds between Copper and Stainless Steel using Gas Tungsten Arc Welding

Abstract

Dissimilar metal joints are used in aerospace industry to combine the unique properties of different materials and to achieve ideal performance and weight savings. The aerospace industry demands for highly reliable structures with less weight and this is always a challenge for material scientists to develop various structures with less weight. This paper describes about the metal joint made between Copper and stainless steel using Gas Tungsten Arc Welding (GTAW). Copper is known for its high thermal conductivity whereas steel has high corrosive resistance and high mechanical strength. This type of dissimilar metal joints can be used in critical aerospace heat exchangers to maintain proper temperature control in spacecraft engine components. Welds are made with and without filler and the weld is analysed. The weld is analysed using EDX. This analysis shows the element composition in the formed intermetallic compound and found that the weldment has a huge amount of element oxides that make the weldment brittle and leads to crack.