Enhanced damage tolerance of Ce-TZP ceramics through a layered architectural design

The outstanding fracture resistance of ceria-doped zirconia-based composites is linked to the formation and development of t-m phase transformation bands under applied mechanical stresses prior fracture. In this work, a layered architectural design combining Ce-TZP-based composite (CTZ) and alumina-zirconia (AZ) embedded layers is proposed to tune the propagation of the stress-induced transformation bands in the CTZ material. Laminates were tape-cast to induce in-plane compressive residual stresses in the embedded AZ layers. Stepwise and continuous 4-point bending loading tests were performed to investigate the formation and extension of transformation bands in the layered design, compared to the reference CTZ material. A larger number of transformation bands with narrower spacing was observed in the laminate, perpendicular to the main tensile stress direction, arresting at the first AZ layer. Higher strength and energy to failure were obtained, showing the potential of the layered design to enhance damage tolerance in Ce-TZP-based ceramics.