In-situ Preparation and Microstructure of Al(Si)/AlN/MgAl₂O₄ Composites

Al(Si)/AlN/MgAl2O4 composites were synthesized by the in-situ reaction from Al-Mg alloy and SiO2 for 2h at temperature of 1473K in nitrogen atmosphere.The products were characterized using microscopy,X-ray diffraction,scanning electron microscopy and energy dispersive X-ray analysis.The phase composition of the composites consisted of MgAl2O4,Al-Si,AlN,Mg2Si and Si.The microstructure of the composites showed that MgAl2O4 spinels were formed by Mg reacted with Al2O3 at the interface of Al/Al2O3.AlN crystal whisker was found in the composites.Some O,Al,Mg,Fe dissolved in the silicon alloy and homogeneously distributed in the composites around ceramic phases were found.