Fracture toughness of alumina matrix composites (AMC)

YSZ solid electrolyte with high fracture toughness as well as enhanced strength is required from a performance and structural reliability point of view. A specific characteristic in fracture toughness measurement according to various methods of advanced alumina matrix composites with particular reference to Al2O3-ZrO2 composites is a main goal of the presentation. The values of the KIC obtained by conventional method on the mechanically notched specimen type SENB (Single Edge Notched Beam) were compared with indentation fracture toughness. Indentation fracture toughness has been determined from direct measurement of the crack length, developed during the Vickers indentation test. The modified method of direct crack measurement has also been used for determination of the fracture toughness. The parameters of subcritical crack growth were determined. Chipping compliance of the alumina matrix composites under different loads applied to the Vickers hardness indenter was tested. The composites Al2O3-10 wt.% ZrO2 with unstabilised ZrO2, yttria or ceria stabilized ZrO2 were tested.