Lab study finds Sc2O3 co-stabilized zirconia pellets resist CMAS penetration better

Increasing the scandium oxide content of scandium oxide–yttrium oxide co-stabilized zirconia pellets improved their measured resistance to calcium-magnesium-aluminosilicate (CMAS) corrosion, according to a laboratory study summarized in the article abstract. Pellets containing up to 6 wt% Sc2O3 showed progressively thinner degradation layers, smaller loose-zone heights and lower effective CMAS penetration depths. The formulation with 6 wt% Sc2O3, designated 6ScY, had the lowest measured degradation and penetration values among the tested materials.

The researchers prepared pellets containing 0–6 wt% Sc2O3 by solid-state reaction, cold isostatic pressing and high-temperature sintering. They examined the pellets’ microstructures, phase constitution, apparent crystallite size, porosity, mechanical properties and behavior after CMAS exposure. Cross-sections of exposed samples were assessed using a scheme that distinguished degraded, loose and dense matrix zones.

Rietveld profile fitting showed that a monoclinic zirconia–yttria–scandia model described the powder patterns of YSZ and 2ScY more closely than those of 4ScY and 6ScY, indicating that the three-phase model had limitations at higher Sc2O3 contents. By contrast, a tetragonal zirconia model satisfactorily described the sintered pellets, supporting a predominantly tetragonal structure. Increasing Sc2O3 content partially suppressed grain growth and increased pellet hardness, but it also reduced the critical crack-growth energy release rate.

These results are limited to the laboratory pellets and the conditions represented by the reported preparation and CMAS-exposure experiments. The supplied evidence does not establish performance in coatings, components or other applications, nor does it provide exact numerical values for the degradation, penetration, hardness or crack-growth measurements. The conclusions are based on the article abstract, because the accessible source text does not include the full experimental results and discussion.

Subject of Research: Experimental evaluation of Sc2O3–Y2O3 co-stabilized zirconia pellets for mechanical performance and CMAS corrosion resistance

Article Title: Mechanical properties and CMAS corrosion behavior of Sc2O3 and Y2O3 co-stabilized ZrO2 pellets

Article References: Liu, Y., Zhang, W., Wang, Z., Yao, X., Zhang, F., Tabie, V. M., Zhong, F., Chen, J., Zou, X., Shao, P., Li, X., Wang, W., & Tu, S.-T. (2026). Mechanical properties and CMAS corrosion behavior of Sc2O3 and Y2O3 co-stabilized ZrO2 pellets. Journal of Materials Science, 61(43), 33479-33501. https://doi.org/10.1007/s10853-026-13778-6

Image Credits: AI Generated

DOI: 10.1007/s10853-026-13778-6

Keywords: zirconia ceramics, Sc2O3 co-stabilization, Y2O3 co-stabilization, CMAS corrosion, mechanical properties, tetragonal zirconia, scandium oxide, yttrium oxide, grain growth, laboratory study, Mechanical, properties