Corrosion Behavior of Sialon Ceramics in Supercritical Water

Abstract

The corrosion behavior of sialon ceramics was investigated in supercritical water at 450°C under 45 MPa for 2–50 h. α‐sialon exhibited better corrosion resistance than β‐sialon and α/β‐sialon. Pitting corrosion with the formation of corrosion products was observed in the case of β‐sialon and α/β‐sialon. By contrast, the corrosion behavior of α‐sialon was characterized by uniform corrosion with the formation of corrosion products. The degree of strength deterioration was strongly dependent on the corrosion morphology. The bending strength of α‐sialon after corrosion for 30 h was about 90% of its initial strength, while the strength of β‐sialon decreased to 65% of its original strength.