Electrochemical properties of sintered polycrystalline α-SiC

Abstract

We have used potentiodynamic polarization curves and Auger electron spectroscopy to determine the characteristic features of the anodic and cathodic behavior in a 0.5 M H2SO4 solution of sintered nonporous samples of polycrystalline α-SiC. We have shown that anodic oxidation of silicon carbide first leads to formation of a surface layer of a solid solution of oxygen in α-SiC, and then a layer of a metastable oxycarbide phase SiC0.67O0.33. We have established that during cathodic polarization, the process of evolution of hydrogen first occurs according to a slow discharge mechanism, and for more extensive polarization it occurs according to a mechanism of surface recombination of atoms.