Oxidation of 6H-α Silicon Carbide Platelets

Oxidation on the 2 crystal faces of SiC platelets was studied. The oxidation of the C face followed a simple parabolic law and was oxide-diffusion controlled, whereas that of the opposite crystal face exhibited a linear growth rate which was surface-reaction controlled. Previous investigators, who studied the oxidation of Sic by measuring weight change, found that the oxidation rate follows a simple parabolic law. At high temperatures and long reaction times, there is an increase in the oxidation rate which has previously been attributed to a change in the state of the oxide. The present investigation, however, indicates that this change occurs as the linear oxidation rate becomes dominant.