Relationship between microstructure and fracture toughness in B2O3-doped 8YSZ ceramics

This study aims to increase the fracture toughness of 8 mol.% yttria-stabilised cubic zirconia (8YSZ) at room temperature owing to the addition of boron oxide (B2O3). Therefore, in this study, the effect of B2O3addition on sinterability and mechanical properties of 8YSZ was investigated using Micro-Vickers hardness tester and scanning electron microscope (SEM). B2O3-doped 8YSZ samples were sintered at different temperatures (1,300-1,500°C). A relative density of approximately 99% was obtained at 1,500°C in the B2O3-doped samples. While the B2O3addition at 1 wt.% content caused a decrease in the grain size of the 8YSZ, and then when the content was > 1 wt.%, it increased. Furthermore, the mechanical properties results showed that fracture toughness of 8YSZ increased with B2O3addition, and the hardness decreased with B2O3addition. Thus, it was found that the fracture toughness of 8YSZ could be improved by B2O3addition. © 2020 Inderscience Enterprises Ltd.. All rights reserved.