The interfacial characterization of oxidized SiC(p)/2014 Al composites

The passive oxidation behavior of SiC particles at elevated temperatures has been studied. The evolution of interfacial reaction products in 2014 aluminum alloy composite reinforced with oxidized-SiC particles after extended thermal exposure at elevated temperatures were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction. Although it could prevent the interfacial reaction between SiC particles and aluminum alloy, the preoxidation of SiC particles resulted in the formation of other interfacial reaction products. The results showed that at elevated temperatures nano-MgO formed initially on the surface of the oxidized SiC particles and then turned into nano-MgAl2O4 crystal due to the reaction between the SiO2 and aluminum alloy containing Mg. TEM observations indicated that the oxidized layer on SiC particles was uniform and had a good bonding with SiC and aluminum alloy.