Formation mechanism of AlN-SiC solid solution by combustion nitridation inSi3N4-Si-Al-C system

The synthesis of solid solutions of AIN-SiC was investigated through the co mbustion reaction between Si3N4, aluminum, and carbon powders and nitrogen gas at pressures ranging from 0.1 to 6.0 MPa, The combustion reaction was i nitiated 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 a mbient pressure (0.1 MPa), The relationship between nitrogen pressure and f ull-width at half-maximum of the (110) peak of the product showed that lowe r pressures produced more-homogeneous solid solutions. Some aspects of form ation of the AIN-SiC solid solutions were discussed with special emphasis o n the influence of nitrogen pressure and reactant stoichiometry.