The Governance of Sintering Regimes on the Properties and Ageing Resistance of Y-TZP Ceramic

Abstract

The retention of nanometric microstructures is a challenge in any presureless sintering process. Grain size influences mechanical properties and grain coarsening retards densification upon sintering, thus resulting in the poor overall product properties. Hence, it is important to select, among others a suitable sintering regime which promotes densification and retards microstructure coarsening. In this work, Y-TZP ceramic bodies were fabricated under four different sintering regimes to investigate the governance of conventional Single-Stage Sintering (SSS) with 1 min and 2 h dwell time, and comparing their performance with bodies produced by Two-Stage Sintering (TSS). It was revealed that TSS sintered samples, yielded better properties than the SSS samples sintered at 1400°C with a dwell time of 2 hours. In the hydrothermal ageing test, TSS samples did not undergo the low-temperature degradation via the martensitic phase transformation of tetragonal to monoclinic symmetry. Nevertheless, it was found by XRD analysis that Y-TZP ceramics sintered by the SSS method using a short dwell time of 1 minute was effective in maintaining the tetragonal phase stability after 50 hours of exposure in superheated steam conditions.