Mechanical properties of alumina-metal-zirconia nano-micro hybrid composites

Abstract

Al2O3 and Al2O3-2 wt% Fe0.8Cr0.2 nanocomposite powders were wet-mixed with different ZrO2 or Y-ZrO2 powders. The influence of the ball-milling medium and mixing duration on the microstructure and the amount of tetragonal zirconia retained after hot-pressing are discussed. The fracture strength and fracture toughness of the alumina-metal-zirconia specimens ave lower than that of the alumina-metal and alumina-zirconia composites. This could result from a partial annihilation of the different reinfor cement mechanisms involved and also from interactions between zirconia and the metallic phase. There is no correlation between the mechanical properties and the amount of tetragonal zirconia. However, the amount of tetragonal to monoclinic transformation at the surface of the specimens during grinding prior to the mechanical tests seems to be a key parameter