Surface-activated bonding between a 3D-printed Ti-6Al-4V structure and bulk aluminum

Surface-activated bonding (SAB) of a 3D-printed Ti-6Al-4V pillar structure (fabricated by selective laser melting) to pure bulk aluminum at room temperature has been investigated. Argon beam irradiation was used to remove surface contaminants and “activate” the surfaces prior to bonding. The surface chemistry of the Ti-6Al-4V surface was analyzed using Electron Spectroscopy for Chemical Analysis (ESCA) to make sure any oxides had been removed by the irradiation procedure. The two materials were successfully bonded via SAB using special bonding apparatus, and scanning transmission electron microscopy (STEM) observation revealed a flat well-bonded interface with no obvious porosity. Furthermore, no thick reaction layer that could compromise the strength of the bond was evident. An oxide layer approximately 2 nm in thickness was observed at the interface by high-resolution TEM, but this is not considered sufficient to have a detrimental effect on bond integrity. The results of the investigation show that 3D-printed materials and structures can be successfully joined to aluminum by SAB techniques.