A study of mechanical properties of alumina–zirconia composite films prepared by a combination of tape casting and solution impregnation method

Abstract

Zirconia-toughened alumina (ZTA) ceramics are one of the most important engineering ceramics with high bending strength and fracture toughness. ZTA ceramics have found important applications in catalysts, implants, wear resistance tools, and electric circuit substrate. The near net shape method based on impregnation of porous body with desired solution has been used to prepare composites with improved properties. In this paper alumina–zirconia composite thin film has been prepared by a combination of aqueous tape casting and solution impregnation methods to improve sintering behavior and mechanical properties. At first, porous 3 mol% yttria-stabilized zirconia was prepared using aqueous tape casting, followed by impregnation with aluminum nitrate solution. Then, the rheological behavior was studied. The microstructure and phase content of samples were studied by SEM and XRD. Microhardness, nanohardness, Young’s modulus, and fracture toughness were measured by Vickers microhardness and nanoindentation methods, respectively. It was found that alumina–zirconia composites with homogeneous distribution of phases and high density can be obtained by solution impregnation method. The mechanical properties of composite thin films prepared by solution impregnation method have been improved compared to those of the composite prepared by tape casting of mixture of alumina and 3YSZ powders.