The Preparation and Properties of Layered TCP/Y–TZP Composites with Ribbon-Like Microstructures

Abstract

The repeated-deformation processing technique was used in the preparation of layered tricalcium phosphate (TCP)/yttria partially stabilized tetragonal zirconia (Y-TZP) composites with ribbon-like microstructures. The fabrication technique involved repeated plastic deformation of layered green tapes, which are stacked together to form starting bi-material laminates, burn-out of the organic vehicle, and sintering at 1300°C. At this rather low sintering temperature, which was chosen to prevent the extensive diffusion of the calcium into the Y-TZP, the zirconia layers could not be fully densified. In spite of the relatively low fractional density (about 75% TD) of these layers, flexural strength values exceeding 100 MPa were achieved with these composites, 150% higher than the matrix material. During autoclaving in water at 200oC for 24 hours no t-m transformation of the zirconia phase took place, indicating full stability of the porous zirconia layers in these composites under the hydrothermal conditions used in this study.