Interfacial microstructure of SiCp/Al composite produced by the pressureless infiltration technique

A SiCp/Al composite was fabricated by the pressureless infiltration of an Al–Mg–Si alloy into the pre-oxidized SiC preform at 1000 °C for one hour. The composite fully infiltrated and a homogenous distribution of SiC particles was confirmed. MgAl2O4 was found as the interfacial reaction product, its formation deriving from the reactions: 2Mg+SiO2=2MgO+Si2Mg+SiO2=2MgO+Si and 2MgO+4Al+3SiO2=2MgAl2O4+3Si2MgO+4Al+3SiO2=2MgAl2O4+3Si. The factors influencing the spontaneous infiltration process were also discussed.