Effect of manganese oxide on the sinterability of 8 mol% yttria-stabilized zirconia

The sinterability of manganese-doped 8 mol% yttria-stabilized zirconia ranging from 0.5-5 wt% was investigated. The role of dopants in the samples was studied in terms of phase stability, microstructures, and mechanical properties. Accordingly, 0.5,1, 3, and 5 wt% manganese were doped into yttria-stabilized zirconia and heated at temperatures ranging from 1300 degrees C to 1550 degrees C. The study revealed that the milling process reduced powder particle size from 0.54 mu m to 0.16 mu m. The grain size of the samples increased with increasing sintering temperature, and adding manganese dopants promoted further grain growth. When sintered at 1450 degrees C, 3 wt% manganese enhanced the densification of the sample to a relative density of 95.8% and Vickers hardness peaked at 14.4 GPa. The samples with manganese dopants exhibited fracture toughness values of 41-4.6 MPa . m(1/2) when sintered at temperatures above 1450 degrees C, regardless of dopant content. Zircon was found on the surface of the sintered sample with over 3 wt% manganese addition but did not disrupt zirconia phase stability. The study showed that the mechanical properties of yttria-stabilized zirconia improved when manganese dopants were added. (C) 2016 Elsevier Inc. All rights reserved.