High temperature oxidation kinetics of SiC particles

The oxidation kinetics of SiC particle in air at the temperature 927℃、1027℃、1127℃was investigated by continuous weighing method in high temperature oxidation furnace.The results show that the oxidation rate constant increases with the rising temperature.Oxidation process of SiC particle can be divided into the earlier and the later period.Oxidation rate was controlled by surface chemical reaction in the earlier period and by diffusion in later period.Apparent activation energy in the later period is much bigger than that in the earlier period.The oxidation process conforms to two-stage model.In the earlier period k_c=143.37exp((-70994)/(RT))(mg·m~(-2)·min~(-1)),In the later period k_D=3.61×10~8 exp((-192758)/(RT)) (mg·m~(-2)·min~(-1))