Microstructural Evolution in Nonvacuum Solid-State Diffusion Bonded Joints of AA2219.

Solid-state diffusion bonding of AA2219 alloy is carried out under the nonvacuum condition to form AA2219/AA2219 joints. In the currently adopted method, AA2219 alloys are joined under the bonding temperature of 450–500°C, bonding pressure of 10 MPa, and bonding time of 30 min. Chemical cleaning is adopted to protect the joining surfaces from reoxidation before the diffusion bonding process. Microstructure evolution at the bonded joints is characterized using optical microscopy, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The hardness at the bonded joints increased with the increase in the bonding temperature. The parent metal structure is achieved at 500°C bonding temperature with an increase in hardness of 112.14 Hv at the bond interface. There is no evidence of intermetallic found at the interface, as confirmed by X-ray diffraction (XRD). [ABSTRACT FROM AUTHOR]