Reaction mechanisms of combustion synthesis of Si3N4-SiC-TiN ceramics

DSC/TG analysis was used to investigate the change of TiSi2-SiC-N-2 system in the temperature range from room temperature to 1400 degrees C. The relationships between Delta G and T about the reactions possible occurring in TiSi2-N-2 system during combustion synthesis were calculated. In order to study the combustion process in detail, the reaction of TiSi2-SiC-N-2 system was stopped at different stages by quenching the samples. The composition and microstructure in different reaction zones were analyzed by means of XRD and SEM, accordingly, reaction kinetic model of TiSi2-SiC-N-2 combustion system was established. The result showed that TiSi2 firstly reacted with N-2 to form TiN and Si, and subsequently Si were nitrified.