LAUSR

Abstract Laminates with alternating layers are well known from nature. The strongly bonded alumina/zirconia (Al2O3/ZrO2) layers can combine high fracture resistance with high strength and stiffness when properly tailored. The presence of compressive residual stresses formed in Al2O3 layers can suppress and deflect cracks propagating through the layers. The crack path is governed by both the elastic properties and the internal stress field of individual layers. The laminates with various layer-thickness ratios ranging from 0.1 to 3 were used to investigate the effect of residual stresses and influence of crack formation pattern on the crack path development. The indentation surface cracks observed in various alumina-zirconia laminates exhibit the same crack deflection independently on the level of internal stresses. The crack deflection observed on the fracture surfaces of bending specimens was related to the indentations cracks. The complicated crack path was explained experimentally by 3D reconstruction with the support of numerical simulations.