Preparation of high-performance zirconia toughened alumina doped with Cr₂O₃ and SrO for artificial joints by spray granulation

Zirconia-toughened alumina (ZTA) ceramics have attracted much attention in the medical field as joint replacement materials due to their good mechanical properties and biocompatibility. However, the flexural strength of conventional ZTA is still slightly insufficient in traditional preparation techniques. In this study, by improving the slurry system, the effects of the solid content of the slurry, additives, and the pH of the slurry on the slurry system were investigated. ZTA powders with a uniform particle size distribution, high degree of sphericity and high flowability were prepared by spray granulation. The mechanical properties, microstructure and biocompatibility of the ZTA pressing were investigated after degreasing and sintering processes. The results showed that the hardness of the prepared ZTA ceramics was 1658.24 +/- 28.04 H V, the fracture toughness was 4.016 +/- 0.027 MPa m1/2, and the biaxial bending strength was 501.43 +/- 21.44 MPa, and the three-point bending strength reached 635 MPa. The ZTA ceramics also possessed good biocompatibility and a low haemolysis rate, which aligns with the requirements of clinical biomedical implant materials.