TWI Industrial Member Report Summary 403/1989
By A Urena and S B Dunkerton
Diffusion bonding of an Al-Li-Cu-Mg-Zr alloy (AA8090) has been investigated. Three different procedures for producing diffusion bonds were examined: solid state bonding with commercially pure aluminium foil of 15µm thickness and diffusion bonding with silver interlayers (coatings and foil) in both the solid and liquid phase. Bonding parameters (temperature, pressure, time and deformation) and post-bond heat treatments (solution and ageing) were examined using both butt and lap joints. Microstructural features and compositional changes in the diffusion zone of joints bonded with the aluminium interlayer were investigated and microhardness measurement was utilised to follow the increase of strength in the interlayer. Tensile (butt joints) and shear (lap joints) tests were used to determine the strength of the bonds.