Investigation of electrical and mechanical properties of 3Y-TZP/Cubic zirconia solid electrolytes with composite structure prepared by near net shape forming

Yttria doped zirconia solid electrolytes with non-equilibrium composite structure were prepared by impregnation of a porous 3Y-TZP matrix with a solution of yttrium nitrate. Microstructures were characterized by XRD and SEM. The electrical properties were studied by impedance spectroscopy as a function of temperature. Biaxial flexural strength and fracture toughness of composite samples were measured by ring on ring and Vickers microhardness indentation methods respectively. The yttria content of the electrolytes was increased by a multi impregnation process. It was concluded that electrical and mechanical properties of the electrolytes can be adjusted by controlling the amount of doped yttria especially if severe sintering treatments are avoided. Electrolytes with conductivity of 0.08 S/cm at 900 °C and fracture strength and fracture toughness of respectively 390 MPa and 2.9 MPa m1/2 were obtained.