High-Strength Mg-PSZ of Fine Grains Containing TiC Particles

Partially stabilized zironia with magnesia (Mg-PSZ) is known as one of the toughest monolithic ceramics. However, the very large grain sizes obtained after sintering at a high solution-heat treatment temperature in the cubic region of the phase diagram limit the strength of this material rather modest. In this study fine-grained Mg-PSZ materials were fabricated by adding TiC particles as a dispersed phase. Samples were hot-pressed at $1750^{\circ}C$ and then annealed at $1420^{\circ}C$ for various times. Grain growth was retarded severely by the TiC particles resulting in grain sizes smaller by more than one order of magnitude than those of PSZ without TiC. The fine-grained microstructure lead to doubly-increased fracture strength while maintaining the same level of high fracture toughness as that of conventional Mg-PSZ without TiC particles.