Study of Al/Ceramic syntactic foams with Al/Si alloy interfaces formed by liquid reaction sintering with silicon-containing vitreous ceramics

Abstract

The novel Al/ceramic syntactic foams with Al/Si alloy phases with excellent interface reactive layer was fabricated by pressure-less infiltration combined with liquid reactive sintering method. Microstructure and interface reactive layer characterization and mechanical behavior of syntactic foams have been investigated by XRD, SEM and EDS. Mechanical properties were used to analyze the effect of interface reactive layer in the syntactic foams. The results showed that ceramic liquid phase generated simultaneously during ceramic phase foaming would react with molten Al to form interface layer. Interface reactive layer formed in composites was composed of Si, Al₉Si and Al_3.21Si_0.47 phases. At the interface region, the content of Si element was increased continuously while aluminum was decreased significantly. The formation of well-bonding interface reactive layer in syntactic foams can be favor to the interfacial load transfer, which exhibits higher compressive strength (73.32 MPa of EG5) in comparison with the compressive strength of ceramic spheres (4.53∼5.32 MPa) and aluminum (∼40 MPa).