Comparison of corrosion behaviors of Sc2O3-CeO2 co-stabilized ZrO2 and YSZ ceramics exposed to CMAS at 1250°C.

In this study, the corrosion behaviors of Sc 0.04 Ce 0.16 Zr 0.80 O 1.98 (SCZ) and YSZ (4 mol% Y 2 O 3 -stabilized ZrO 2) in CMAS (Ca-Mg-Al-Si) at 1250 °C were investigated systematically by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscope (FE-SEM), and field emission transmission electron microscope (FE-TEM). The results showed that Y3+can be easily precipitated from YSZ and diffused into the CMAS molten salt due to high solubility in the CMAS corrosion environment, prompting the transition from the tetragonal (t) phase to the monoclinic (m) phase. During the corrosion of YSZ powder, the reverse migration of Mg and Ca into the lattice increased the stabilizer content in part of the YSZ crystal lattice, resulting in the generation of a small amount of cubic (c) phase. For SCZ materials, the stabilizer CeO 2 was chemically inert in the CMAS environment. Sc3+ had low solubility and poor affinity with Ca2+, and can only be readily precipitated from the surface layer of the ceramic bulk with high CMAS concentrations, which led to the generation of the m phase. The SCZ material had better resistance to CMAS corrosion and t phase stability than the YSZ material. • The SCZ material has better resistance to CMAS corrosion and better t phase stability than the YSZ material. • Compared with Y3+, Sc3+ has lower solubility and poorer affinity with Ca2+ in the CMAS environment. • The stabilizer CeO 2 is chemically inert in the CMAS and stably present in the ZrO 2 crystal lattice. [ABSTRACT FROM AUTHOR]