Transient liquid phase diffusion bonding of Al/Al₂O₃ nanostructured metal matrix composites

Abstract

Transient liquid phase (TLP) diffusion bonding was carried out on nanostructured metal matrix composite sheets of Al-1100 alloy with 5 wt-% alumina particles at various bonding temperatures and process durations. A thin layer of 5 mm pure copper was electrodeposited as an interlayer. Joint formation was first attributed to the solid state diffusion of copper into the aluminium metal matrix followed by eutectic formation; then, base metal dissolution and isothermal solidification was completed at the joint interface. Joint area was characterised using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Diffraction patterns showed the formation of intermetallic phases like CuAl 2 . The concentration of Al 2 O 3 particles increases across the interface as the bonding temperature increases. As a result, the highest bond strength of 123 MPa was achieved after a bonding duration of 30 min at 590uC.

Availability of in-situ reinforced active-transient liquid phase bond with good wettability for 70 vol.% SiCp/A356 composite using Al-Mg-Ga-Ti interlayer

“…Therefore, brazing and transient liquid phase bonding (TLP) were extensively attempted. In comparison to conventional brazing, TLP bonding using an interlayer containing sufficient melting point depressant (MPD) offers the following benefits: (1) omitting of flux for removing oxide film owing to undermining of substrate oxide caused by the diffusion of MPD into substrate [2][3][4][5][6][7][8][9][10], (2) achievement of solid-solution bond seam by isothermal solidification, and (3) lower bonding temperature for avoiding potential thermal degradation of substrate materials. The micro-interface between Al-MMCs composite and metallic interlayer can be subdivided into two types: matrix/metal (M/M) and particle/metal (P/M) interfaces [11].…”