A new arrangement of SiC particles in reaction bonded Si3N4-SiC ceramic refractory and crack behaviors under thermal shock

High temperature protection brick lining is important for super-charged boilers. In practice, Si3N4 bonded SiC ceramics are usually chosen as the raw material of refractory bricks due to their excellent performance under high temperature. In the field of the ceramic refractory material, a main goal is to improve the resistance of ceramics under thermal shock because their inherent brittleness may cause failure under sudden change in temperature. In this paper, we fulfilled this goal by introducing a new particle arrangement called “double dispersion” for the SiC particle-reinforced ceramic refractory material. And we established the micro-structure models for both the original and the modified ceramic refractory material. To study the influence of the particle arrangement on the fracture toughness, we performed simulations of the crack initiation and propagation under the same thermal load for the original and the modified material. The results showed that the “double dispersion” method can improve the thermal shock resistance of the reaction-bonded Si3N4-SiC ceramic refractory.