Abstract
Nanocomposites are noticed its remarkable improvement of mechanical. But, strengthening and toughening mechanisms of nanocomposites as structural materials are not clarified up to now. It is necessary to clarify the strengthening and toughening mechanisms for increasing the reproducibility and reliability in naocomposites. In this presentation, we proposed new design concept of strengthening and toughening mechanisms in nanocomposites. To fabricate the nanocomposites, we prepare mixtures of ceramic/metal raw materials obtained from g -alumina powder as matrix and metal acid form as secondary particle. Then, we sinter using PECS technique. We measure fracture strength and fracture toughness using three-point bending test and SEVNB (single edged V-notch beam) technique, respectively, and calculated FPZ (frontal process zone) size based on a local fracture criterion. Fracture mode transformation from intergranular fracture to transgranular fracture is a typical feature of nanocomposites. Toughening mechanism is explained due to relationship among fracture strength, fracture toughness and FPZ size.
