Fabrication of High-Strength Zr-Based Composites by Spark Plasma Sintering

Zirconium (Zr) partially stabilized zirconia (PSZ) composites were fabricated using the spark plasma sintering technique with the aim of producing medical implants with reduced metal-related artifacts in magnetic resonance imaging. Composites with compositions ranging from 100% Zr to 100% PSZ were fabricated, and they exhibited high mechanical performance. Optical microscopy and density measurements revealed that dense composites were successfully produced, irrespective of the PSZ content. Hardness and bending tests were performed to evaluate the influence of the addition of PSZ on the mechanical properties of the composites. The results showed that the hardness and bending strength increased with increasing PSZ content. The elastic modulus of the composites was higher than that predicted by the rule of mixtures, and this was due to the formation of Zr oxide around the Zr phase during sintering. It was concluded that the mechanical properties of the composites could be controlled within the range of those of monolithic Zr and monolithic PSZ, and that the use of PSZ was effective for improving the mechanical properties.