Dynamics Research on Non-isothermal Oxidation Reaction of AlN Powder

The process and dynamics parameters of non-isothermal oxidation of AlN powder(d50=5μm) were studied by TG-DTA and XRD in atmosphere of 4/5N2 and 1/5O2 mixture with flow rate of 55mL/min and heating rate of 10℃/min.The results showed that the AlN powder obviously began to be oxidated and its mass increased over 900℃.The process of dynamics of oxidation reaction between AlN and O2 was controlled alternately by reaction and diffusion.Non-isothermal oxidation dynamics parameters(activation energy E,reaction orders n and pre-exponential factor A) of the AlN powder were obtained by the experimental data.E equals about 417.4kJ/mol,n about 2.9 and A about 3.47×1012h-1.Due to smaller activation energy E and larger pre-exponential factor A in dynamics parameters of AlN powder non-isothermal oxidation,AlN powder is easily oxidated with larger oxidation reaction rate at high temperature and air.Actual measurement thermogravimetric curve is in agreement with theoretical calculation.It shows that the dynamics equation based on these dynamics parameters data of non-isothermal oxidation of d50=5μm AlN powder is reasonable.