Formation mechanism of AlN-SiC solid solution by combustion nitridation in Si3N4-Si-Al-C system

The synthesis of solid solutions of AIN-SiC was investigated through the combustion reaction between Si3N4, aluminum, and carbon powders and nitrogen gas at pressures ranging from 0.1 to 6.0 MPa, The combustion reaction was initiated locally and then the wave front propagated spontaneously, passing through the cylindrical bed containing the loose powder. In the presence of Si3N4 as a reactant, it was feasible to synthesize solid solutions at an ambient pressure (0.1 MPa), The relationship between nitrogen pressure and full-width at half-maximum of the (110) peak of the product showed that lower pressures produced more-homogeneous solid solutions. Some aspects of formation of the AIN-SiC solid solutions were discussed with special emphasis on the influence of nitrogen pressure and reactant stoichiometry.