Microstructure and mechanical properties of zirconia ceramics consolidated by a novel oscillatory pressure sintering

Abstract Zirconia ceramics with high density and fine, uniform grains were consolidated by a novel oscillatory pressure sintering (OPS) approach. Compared with the zirconia ceramics by hot pressing (HP) at the same sintering temperature, grain sizes of the OPS specimen were distributed in a narrower range with average size of 278 nm; besides, the anisotropic grain growth was inhibited by oscillatory pressure, resulting in a smaller difference between the long radius and the short radius than the HP specimen. Due to microstructure evolution, the flexural strength of the OPS specimen reached approximately 1549 MPa, and the load-displacement behaviors were also improved. Such evolutions in microstructure and mechanical performances were ascribed to the new densification mechanisms induced by oscillatory pressure.