Kinetics of High-Temperature Oxidation of Inorganic Nonmetallic Materials

A series of new formulae have been developed for describing the kinetics of solid-gas reactions with an emphasis on diffusion control. Compared with traditional methods, these new equations can be used to treat not only sphere samples but also cylinder, cuboid, and cube samples. Different from the traditional methods, all the parameters in our formulae have a clear physical meaning; as a result, they are easy to use and convenient for theoretical discussion. Based on these equations, one may further estimate the influence of the sample shape on the kinetic behavior. It is shown that the calculation errors based on our new models are less than those of traditional models such as the Jander, the Ginstling-Brounshtein as well as the parabolic model. Besides, a new concept of "characteristic oxidation time" has been suggested to measure the oxidation resistance of various materials, which might be useful for evaluating the possible applications of different inorganic nonmetallic materials.