Effect of large thicknesses on the characteristics of laminated ZrO-Zr₂CN/Si₃N₄ ceramics by reactive hot pressing

Tape casting and reactive hot pressing are employed to fabricate laminated ZrO-Zr₂CN/Si₃N₄ ceramics with various large thicknesses of Si₃N₄ layers, and the effects of thicknesses of the Si₃N₄ layers on the characteristics of the laminated ceramics were investigated. With increasing the thicknesses of Si₃N₄ layers, the flexural strength and Young's modulus of the laminated ceramics increased while the fracture toughness decreased, and the contents of ZrO and ZrO₂ at the surfaces of Zr particles after organic removal process which were the key factor of the morphologies of ZrO-Zr₂CN layers and interfaces. With the increase of residual compressive stresses in Si₃N₄ layers, work of fracture and left tail in flexural stress-displacement curves increased. The laminar structure with large thickness obtained well strengthening effect and high damage tolerance.