Differences in microstructure and mechanical properties between Y-TZP and AL2O3-doped Y-TZP/bioglass ceramics

Abstract

Y-TZP (YZ) and Al2O3-doped Y-TZP (AYZ) bioceramics with addition of different contents of a refractory bioglass were fabricated. The influence of the glass addition and sintering temperature on the densification behavior, microstructure, and mechanical properties of YZ and AYZ was studied. The developed ceramics contained small amounts of ZrSiO4 and Ca2P2O7 phases within the ZrO2 matrix. The incorporation of glass to YZ promoted the ZrO2 phase partitioning and enhanced the ZrO2 grain growth at all the sintering temperatures, whereas the glass addition in AYZ prevented the Y2O3 redistribution between ZrO2 grains and limited the ZrO2 grain growth at 1300–1400°C. The hardness of the samples with glass was not significantly altered by using either YZ or AYZ. A slight increase in the fracture toughness with increasing glass content was found for YZ, while the fractured toughness of AYZ decreased by the glass addition. The more pronounced ZrO2 phase partitioning of YZ with glass decreased the flexural strength, whereas AYZ maintained almost unaltered its flexural strength at a high level by the glass incorporation.