Ceramic nanocomposites: mechanical properties

The high strengths reported for ceramic nanocomposites are not caused by an increase in toughness. They are probably caused by a reduction in processing and contact induced defect density coupled with an enhanced crack healing mechanism on annealing. Transgranular fracture is an important indicator of the strength increase and this associated with reinforcement particles located on grain boundaries. Enhanced creep resistance is associated with grain boundary pinning mechanisms. The mechanisms for the increased wear resistance are not yet known.