Combustion Synthesis of β-SiAlON

摘要

Since β-Si6-z AlzOzN8-z (0 ＜z ≤ 4.2) was discovered in the early 1970s,it has been developed actively owing to their excellent mechanical and thermal properties.This material has been conventionally produced from a mixture of Si.3N4,AIN,Al2O3 and sintering aids such as Y2O3 based on Solid-State Reaction (SSR) method,in which it was kept at high temperature for long time,causing time-and energy-consuming.To overcome this problem the Combustion Synthesis (CS) has been proposed and the scale-up equipment is now under planning.In this paper,the cutting-edge technology on the combustion synthesis of SiA1ON is reviewed.In this process,once one end of mixed powder of Si,A1,SiO2/A12O3,SiAlON as diluent is ignited at pressurized nitrogen of 1 Mpa,the reaction wave propagates to another one sustainably due to strong exothermic heat without any additional energy in short time.To improve the yield of the product in the combustion synthesis,a diluent was needed to lower adiabatic temperature.The fine powder obtained was sintered by Spark Plasma Sintering (SPS).The CS process will offer many benefits for saving energy,minimizing operating time,producing fine powders without post crushing process,eliminating sintering aids,and cutting total productive cost.The results also appealed a new possibility of SiAlON production for the wide application such as photoluminescence.