Fabrication and characterisation of AZ91/SiC composite by pressureless infiltration method

Abstract

Since the spontaneous infiltration of molten AZ91 Mg alloy into the powder bed containing SiC particles occurred at 700°C for 1 h under a nitrogen atmosphere, it was possible to fabricate Mg alloy composites reinforced with SiC particles. Since the fabrication conditions (e.g. temperature, time and atmosphere) of the composite are different from those of the other fabrication route, reaction products formed during the composite fabrication were investigated in detail using field emission scanning electron microscopy and high resolution transmission electron microscopy. From the analysis of reaction products, the authors can identify the formation of MgO, MgAl₂O₄, Al₁₂Mg₁₇ and an AlN phase containing magnesium.