Reaction mechanism for combustion synthesis of β-SiAlON by using Si, Al, and SiO2 as raw materials

β-SiAlON (z = 1) was combustion synthesized by slowly heating the raw mixture of Si, Al, and SiO2 under a constant nitrogen pressure of 1 MPa. The temperature record showed several exothermic and endothermic reactions during the entire process and two main exothermic reactions at ∼800 °C and ∼1350 °C. The measured ignition temperature was approximately 1350 °C. The total enthalpy of reaction estimated from the two exothermic reactions was 592.62 kJ/kg.

► Intermediate reaction process and the reaction mechanism were studied. ► Exothermic reactions at ∼800 °C and ∼1350 °C are due to Al and Si nitrification. ► The ignition temperature for combustion synthesis of β-SiAlON is 1350 °C. ► The enthalpy of reaction is estimated to be 551 kJ/kg.