Diffusion bonding of superplastic 7075 aluminium alloy

Diffusion bonding (DB) of superplastic 7075 Al alloy has been investigated for various temperatures, pressures and times, using a Gleeble 1500 test ma chine. After the removal of surface oxide, an organic solution was used to protect the surfaces prior to bonding. The strengths achieved after bonding were dependent on interface grain boundary migration and on grain growth d uring the bonding profess. Under optimum conditions, bonds having parent me tal shear strength and microstructure were obtained. The optimum temperatur es for diffusion bonding, 510-520 degrees C, corresponded with those at whi ch the material exhibited optimum superplastic behavior. The characteristic s and mechanisms of bonding are discussed. (C) 1999 Elsevier Science S.A. A ll rights reserved.