Freeze cast symmetric three-layer alumina-matrix composites with improved damage resistance Original Research Article

Symmetric three-layer Al2O3/m-ZrO2/t-ZrO2 composites have been prepared by sequential freeze casting followed by pressureless sintering at 1400–1600 °C in air. The layered material densified at 1600 °C exhibited a maximum fracture strength (235 MPa) and toughness (6.72 MPa m1/2). Contact damage resistance was superior in the layered composite when compared with monolithic ceramic, possibly due to the development of relatively large compressive stresses in the outer layers.