The preparation and properties of Al2O3–ZrO2 composites with corrugated microstructures

Zirconia-toughened alumina (ZTA) composites with a corrugated microstructure were prepared from viscous non-polar suspensions of alumina and zirconia powders. Two alumina and one zirconia layers of 1 mm thickness was stacked and rolled together to form 1 mm thick laminates, which were then repeatedly folded and rolled, each time with a 50% reduction in thickness. The transition from laminar to corrugated microstructure was controlled by the rheological properties of the suspensions and the number of plastic deformations. The shrinkage of composites during sintering was between that of the shrinkage of single layers of alumina and zirconia and no sintering cracks were observed after three foldings. The mechanical properties of sintered composites improved with structural refinement. The flexural strength and KIc for the final composite were 710 MPa and 7.1 MPa√m, respectively.