ANODIC OXIDATION OF SiC-TiB2-B4C COMPOSITES IN 3% NaCl SOLUTION

Polarization curves and Auger spectroscopy are used to study the kinetics, formation mechanism, and layer-by-layer phase composition of oxide films resulting from the anodic oxidation of SiC-TiB2-B4C ceramics containing 10 wt.% and 40 wt.% TiB2 in 3% NaCl solution. It is shown that a two-layer oxide film forms in the former case (beta-Ti2O3 is the lower layer and TiO2 the upper one) and a three-layer film forms in the latter case (nonstoichiometric beta-TiO is the upper and lower layers and beta-Ti2O3 the intermediate one). All ceramic samples, especially those with 10 wt.% TiB2, have high corrosion resistance.