Predictability of the Mechanical Properties of Inclusion‐Containing Ceramics

The incorporation of inclusions into a brittle matrix can change its properties significantly. The quantitative change of strength, toughness, and retained strength after severe thermal shock and Vickers indentation damage in so‐called “duplex ceramics” can be reasonably well predicted by relating these properties to the empirically derived internal stress‐intensity factor K 1 . In the present paper the relationship between K 1 and three other recently measured properties—flaw resistance behavior, K R ‐curve behavior, and Stress–Strain behavior—is investigated. In addition, the strength‐degrading influence of pressurized inclusions observed in “duplex ceramics” is compared to the strength reduction and enhancement reported by other authors for composites containing a glass matrix and glass and alumina inclusions. An attempt is made to identify the important parameters which control the strength development in duplex structures.