Zirconia on the properties of pressureless sintered fluorohydroxyapatite/zirconia composites

摘要

In this study, fluorine-substituted hydroxyapatite (Ca-10(PO4)(6)(OH)(0.8)F-1.2; coded as HA06F) and yttria-stabilized zirconia (YTZP) were prepared by a sol-gel method to produce HA06F-YTZP composites with 5, 10, 15, 20, 40, and 60 wt% YTZP by pressureless sintering. Phase and microstructural analysis showed that the thermal stability of the HA06F matrices could be maintained when the YTZP content did not exceed 20 wt% and for sintering temperatures less than 1400 degrees C, while the YTZP phase retarded the densification of the composites if the zirconia content was over 20 wt%. High resolution TEM obervation revealed that the reaction between the HA06F phase and the zirconia phase was suppressed. Mechanical properties including the Knoop hardness, the Young's modulus, and the fracture toughness of the HA06F-YTZP composites increased with the YTZP content until the optimal content of 20 wt%, while further increasing of the YTZP contents led to lower mechanical properties.