8 mol% Y2O3-stabilized zirconia (8YSZ) transparent ceramics with high optical and mechanical performance through YF3 sintering additive

Abstract

In this study, YF₃ was utilized as a novel sintering additive in fabricating high-performance 8YSZ transparent ceramics. A series of undoped and YF₃-doped 8YSZ transparent ceramics were fabricated through air pre-sintering combined with hot isostatic pressing (HIP). The influence of the YF₃ content on the sintering behavior, microstructure, and optical properties of the 8YSZ transparent ceramics was systematically investigated. In detail, the addition of YF₃ (0.02–0.2 wt%) significantly enhanced densification, while exerting negligible effects on grain growth. Notably, excessive YF₃ (>0.1 wt%) induced volatile gas evolution, resulting in residual porosity and reduced densification efficiency. By employing optimized processing conditions (0.1 wt% YF₃ additive and HIP at 1550 °C), the as-prepared 8YSZ transparent ceramic exhibited superior optical and mechanical performance. The optimal properties included 71.4 % in-line transmittance at 600 nm (∼94 % of the theoretical limit), Vickers hardness of 12.4 ± 0.3 GPa, and flexural strength of 329 ± 38 MPa. These results highlight the beneficial effect and criticality of content control for YF₃ additives in achieving high-quality transparent 8YSZ ceramics.