The Mechanical Properties and Microstructure of Zirconia Toughened Alumina Bioceramics for Implant

초록

The microstructures and mechanical properties of Al2O3/3Y-TZP ceramic composites with 3Y-TZP content ranging from 0 vol% to 30 vol% were investigated in this study. The ceramic composites were fabricated by means of cold isostatic pressed at 150MPa and the green compacts were sintered at 1600˚C for 2h. After grinding and polishing, physical and mechanical properties such as relative density, Young’s modulus, fracture toughness, flexural strength, and hardness were evaluated. The relative densities of all composites were above 99%, the values of hardness, fracture toughness and flexural strength increased with the increasing content of 3Y-TZP, while the Young’s modulus showed the contrary tendency. The toughening mechanisms and reliability analysis, and low temperature ageing was carefully investigated. The strength and fracture toughness of Al2O3/3Y-TZP ceramic composites increased mainly due to development of residual compressive stress and grain size refinement. The Weibull modulus increased by the addition of 3Y-TZP. There was no phase transition of 3Y-TZP from tetragonal to monoclinic and strength drop after low temperature ageing experiment (134oC in water, 36h).