• Charkaluk, Eric
• Benoist, Julien
• Krishnamurthy, Sanjay Channappa
• Simar, Aude
• Dimov, Nicolas

Abstract

With increasing use of lightweight materials such as titanium (Ti) and aluminium (Al) in multiple high production value industries such as aerospace and automobile, the demand for welding of dissimilar metals has significantly increased in recent years. Conventional fusion welding faces multiple challenges however: notably different thermal expansion coefficients of both materials leading to high residual stresses, remarkably melting temperatures. In this work AA6061-T6 and Ti-6Al-4V (Grade 5) alloys are joined by Friction Stir Welding (FSW) and Friction Melt Bonding (FMB). The FMB is another friction-based assembly process inspired by FSW, which shows promising results in the joining of aluminum to steel by local melting of the aluminum[1]. FSW welds formed a strong joint withdispersed Ti-Al intermetallics and mechanical interlocking of both materials. During a single lap shear test of the dissimilar joint, the weld fails at the titanium side, which ensure the interface has a strong welding strength. Preliminary FMB welds also demonstrated promising welds, by interlocking mechanism of Al metal flow into Ti at the interface. Various bands with the mixing of Al within the Ti in vortices like appearance also observed on the Ti plate in those FMB joint, which ensure the possible mechanical interlocking in those welds. FMB Ti-Al welds didn’t showcase any detectable intermetallic during SEM observations. These original observations merit to be further investigated to better suit Ti/Al welding for industrial applications

Topics

• impedance spectroscopy
• scanning electron microscopy
• melt
• aluminium
• strength
• steel
• shear test
• aluminium alloy
• thermal expansion
• titanium
• intermetallic
• joining
• melting temperature