Vacuum Diffusion Bonding of Dissimilar Metal Alloys AA۲۲۱۹ and Ti-۶Al-۴V: Influence of Bonding Pressure on Microstructure and Mechanical Properties of the Bonding Joint

Dissimilar joints of AA۲۲۱۹ and Ti-۶Al-۴V alloys are obtained using the vacuum diffusion bonding method. The bonding pressure is controlled in the range of ۱-۴ MPa by keeping the bonding temperature and holding time constant. The influence of the bonding pressure on the microstructure and mechanical properties of the bonding joints is investigated. The diffusion behaviour across the interface of the bonding joints is increased with the increase in bonding pressure. The interface morphology of the specimen bonded at lower bonding pressures exhibits scraggly voids and cracks. The irregular voids and cracks are squeezed and gradually closed due to the significant increase in the diffusion between Al and Ti. The maximum shear strength of ۸۱ MPa is obtained for the joint made at the bonding pressure of ۴ MPa, and a diffusion layer of ۰.۷۶ µm is formed at the Ti side interface. The fracture morphology inferred the brittle failure of the bonding joints due to the formation of intermetallic compounds like TiAl, TiAl۲, and TiAl۳ at the interface of Al and Ti.

کلیدواژه ها:

AA۲۲۱۹ ، vacuum-diffusion ، interface and fracture morphology ، microstructure ، mechanical property.