Hydrothermal Corrosion of Alumina Ceramics

Abstract

The corrosion behavior and strength degradation of alumina ceramics with 99%, 99.9%, and 99.99% Al 2 O 3 were studied in water at 300°C and 8.6 MPa for 1 to 10 d. The weight loss in alumina ceramics was mainly attributed to the dissolution of SiO 2 and Na 2 O grain‐boundary impurities. Intergranular corrosion proceeded in the alumina ceramics by preferential attack at the grain boundaries. The extent of the strength reduction for corroded alumina ceramics was related to the impurity level in the alumina ceramics.