FLAW-INSENSITIVE CERAMICS

Ceramics are notorious for their 'brittleness', i.e. the sensitivity of mechanical strength to flaws on the microstructural scale. The associated notion of the 'critical flaw' has dominated design considerations concerning structural reliability and materials processing of ceramic components. This accounts for the trend over the last decade towards a processing strategy of elimination strength-degrading flaws at source. Here we propose a fundamentally different approach, that of processing ceramics with crack-impeding elements integrated into the indigenous microstructures, such that any pre-existing or service-induced flaws are effectively stabilized. Strength data on a tailored alumina/aluminium-titanate material demonstrate the capacity of our approach to produce simple ceramics with unique flaw insensitivity.