Abstract
Si3N4 is one of the most promising structural ceramics due to its unique properties, while the large scale applications are still limited by its high cost and low reliability. Combustion synthesis (CS) is a feasible approach to synthesize Si3N4 in large scale and low cost. This work focused on the mechanism of CS Si3N4 during commercial production process. Temperature profile analysis of the on-line measured data indicates that the conversion ratio was only 40% when combustion reaction temperature reached the highest value. Post-combustion nitridation could last as long as 660s. A model was proposed to account for the combustion synthesis of α-Si3N4, the CS process was optimized to regulate the phase composition and particle size of the combustion-synthesized product. Based on the understanding of the Si-N2 reaction, a breakthrough was achieved ---- a new method of CS of Si3N4 at normal nitrogen pressure was established.
