Resistance of pure and mixed rare earth silicates against calcium‐magnesium‐aluminosilicate (CMAS): A comparative study

• DOI: 10.1111/jace.17328
• Publication Date: 2020-06-22T18:36:25Z
• Authors: Markus Wolf; Daniel Emil Mack; Olivier Guillon; Robert Vaßen
• Keywords: Ytterbium; Calcium silicate

Abstract Rare earth silicate environmental barrier coatings (EBCs) are state of the art for protecting SiC ceramic matrix composites (CMCs) against corrosive media. The interaction four pure rare EBC materials Yb 2 SiO 5 , Si O 7 Y and three ytterbium mixtures with molten calcium‐magnesium‐aluminosilicate (CMAS) were studied at high temperature (1400°C). samples characterized by SEM XRD in order to evaluate recession different after a reaction time 8 hours. Additionally, coefficient thermal expansion (CTE) was determined suitability as CMCs. Results show that monosilicates exhibit lower contact CMAS than their disilicate counterparts. silicates is far yttrium under attack. Investigation exposes superior resistance CMAS, which even higher monosilicate. Also decreased CTE suggests they will display better performance