Effect of Process Parameters on TIG Weld-Brazing of Aluminum Alloy to Galvanized Steel

Krishna P. Yagati; Shibin A V; Jobin Joseph; Pablo S Ezhuparayil; Sherin Thampi; Tony Chacko

Abstract

AbstractAbility to join aluminum alloy to steel enables weight reduction of automobile bodies. Gas tungsten arc welding (GTAW) process was employed to weld-braze A8011-H14 aluminum alloy to galvanized steel in lap configuration. The influence of heat input on bead formation and joint strength was investigated. The microstructural characterization was carried out using an optical microscope and scanning electron microscope. The chemical composition was analyzed using energy dispersive spectroscopy technique. The various regions of microstructural interest are aluminum/bead interface, bead and bead/steel interface. The microstructural analysis revealed the presence of reaction layer formed at bead/steel interface due to diffusion between molten aluminum and solid steel. The reaction layer was found to vary in thickness and morphology throughout the bead/steel interface. The joint was tested under lap-shear condition using universal testing machine. Heat input showed a remarkable effect on the bead formation and mechanical properties of the joint. The joint made at 75 A current recorded a fracture load of 2.4 kN. Keywords: Aluminium-Steel Dissimilar, Brazing, Gas Tungsten Arc Welding (GTAW), IntermetallicsCite this ArticleTony Chacko, Shibin A.V., Jobin Joseph, et al. Effect of Process Parameters on TIG Weld-Brazing of Aluminum Alloy to Galvanized Steel. Journal of Thin Films, Coating Science Technology and Application. 2018; 5(3): 8–14p.