Synthesis and characterization of in situ Al-AlN composite by nitrogen gas bubbling method

In situ Al-AlN composite with and without Mg addition was synthesized by nitrogen gas bubbling method. The morphology of the particles was found to be hexagonal by SEM and TEM. The size of the AlN particles was found to be in the range from nano, submicron to a few microns. XRD analysis of the extracted particles confirmed the formation of AlN in the melt. Mg addition enhanced the nitridation rate and formed network of interconnected AlN particles. Hardness of the composite is significantly increased by the hard AlN particles. Further, the mechanism of formation of AlN particles inside the molten aluminium by gas bubbling is discussed. (C) 2010 Elsevier B.V. All rights reserved.