Introduction to a tough, strong and stable Ce-TZP/MgAl2O4 composite for biomedical applications

The processing of a new ceria-doped tetragonal zirconia polycrystal-based (Ce-TZP) composite and its microstructural and mechanical features are presented. Slip casting and die pressing were used to process commercially available Ce-TZP and MgAl2O4 powders into a dense ceramic composite. The absence of tetragonal to monoclinic transformation under hydrothermal conditions was assessed during accelerated aging tests. Biaxial flexural strength and fracture toughness values of more than 900 MPa and 15 MPa √m, respectively were measured, showing that phase transformation toughening of zirconia is maintained in the composite, while the inter/intragranular dispersion of nano-scaled magnesia spinel leads to strengthening of the Ce-TZP matrix. Flaw tolerance is attained, since the strength appears to be transformation dependent. These properties allow the composite to be used in the fabrication of various load-bearing components by employing conventional processing methods and sintering, for example for structural biomedical applications.