Residual stresses in layered ceramic composites

Laminar composites containing layers of Y-TZP or Ce-TZP and either Al2O3 or a mixture of alumina and zirconia have been fabricated using a sequential centrifuging technique of water solutions containing suspended particles. Controlled crack growth experiments with notched beams of composites showed the significant effect of barrier layer thickness and composition on crack propagation path during fracture. Distinct crack deflection was observed in alumina layers. In the case of layers made of an oxide mixture, crack deflection was not found independently on layer thickness. The observed changes have been correlated with distribution of residual stresses in barrier layers created during cooling of sintered composites from fabrication temperature. (C) 1999 Elsevier Science Limited. All rights reserved.