Anodic dissolution of solid‐state sintered silicon carbide at high current densities

Abstract

The electrochemical behavior of solid‐sintered silicon carbide was investigated under high current densities in alkaline solutions. The use of potentiodynamic as well as chronoamperometric measurements show that the anodic dissolution takes place as a transpassive mechanism under formation of a metastable passive layer. At high polarization potentials (≈150 V), the dielectric breakdown of the passive layer which was primarily formed on the surface initiates an anodic dissolution of sintered silicon carbide at high current densities. Complementary material diagnostics (optical microscopy and SEM/EDX investigation) clearly show significant material removal as well as remaining oxide layer thicker than the native oxide film.