Fabrication and characterisation of AlN-SiC porous composite ceramics by nitridation of Al4SiC4

AlN-SiC porous composite ceramics were fabricated by heat-treating Al4SiC4 porous ceramic green body prepared using the foaming method under flowing nitrogen. The porous structure could provide increased nitrogen diffusion channels, leading to a decrease in N-2 diffusion resistance and an increasing degree of nitridation. The micro-morphology of AlN was in the form of particles or whiskers and influenced by heating temperature and time parameters. AlN has good dispersibility with SiC particles, resulting in local homogeneous chemical composition of prepared AlN-SiC composite ceramics. Furthermore, the potential reaction mechanism responsible for the synthesis of AlN-SiC porous composite ceramics during the nitridation was revealed. This simple approach may be used for large-scale synthesis of AlN-SiC porous composite ceramics.