Experimental analysis and numerical simulations of the mechanical properties of a (Ce,Y)-TZP/Al₂O₃/H6A ceramic composite containing coupled toughening mechanisms.

Abstract

This study investigates the simulation of the mechanical behavior of a bioceramic composite based on (Ce,Y)-TZP reinforced with equiaxed Al₂O₃ and platelet-shaped hexaaluminate (H6A) grains using Finit Element Method (FEM). A commercial (Ce, Y)-TZP/Al₂O₃ ceramic powder was compacted into disc-shaped specimens that were sintered at 1500 °C for 2 h. The sintered samples were further subjected to hydrothermal degradation in an autoclave at 134 °C, 0.2 MPa, for 10 h and characterized according to their phase composition, microstructure, and relative density. Their flexural strength values were determined by the piston-on-three-ball test, and Weibull statistics was used to evaluate the results. Their hardness, fracture toughness and elastic parameters were also measured. Numerical simulations of the biaxial strength test were performed using the ABAQUS finite element code. The sintered ceramic composite material presented relative density >99%, high resistance to hydrothermal degradation, average hardness of 1435 ± 35 HV, fracture toughness K_IC of 9.7 ± 0.5 MPa m^1/2, and average biaxial flexural strength of 952.6 ± 88 MPa. The numerical predictions of the biaxial flexural strength showed a consistently lower average biaxial flexural strength value of 880.9 MPa, ∼10% lower than the average experimental results. The differences observed are attributed to the complex coupled toughness mechanisms of this material, not included in the finite element simulations.