Estimation of critical frontal process-zone size in porous ceramics

Abstract

The size of frontal process-zone at a crack tip is important to estimate toughening mechanisms of ceramics. Three-point flexural test was carried out for porous silicon carbide containing a sharp V-notch with different size. The critical size was determined as the distance between the notch tip and the characteristic point, where the critical local stress was equal to the flexural strength of the specimen. Porous ceramics showed obviously the enlarged critical frontal process-zone, compared with dense ceramics.