Fabrication and mechanical properties of Al2O3–Si3N4/ZrO2–Al2O3 laminated composites

In this paper, Al2O3–Si3N4/ZrO2–Al2O3 laminated composites were fabricated by tape casting and hot press sintering, and the relationships between the process, microstructure, and mechanical properties of Al2O3–Si3N4/ZrO2–Al2O3 laminated composites were determined. The SiAlON phase was found in the Al2O3–Si3N4 layer, and liquid-phase sintering was proposed. Nano-scratch tests were carried out to investigate the interface bonding strength of the laminates. The distribution of residual stresses, generated due to the different coefficients of thermal expansion between the different layers, was estimated according to lamination theory and confirmed using Vickers indentation. When the sintering temperature was 1550 °C, the sintered laminated ceramics had good mechanical properties, with a maximum strength and toughness of 413 MPa and 6.2 MPa m1/2, respectively. The main toughness mechanics of laminated composites was residual stress.