Chemical and mechanical properties of modified Yb2Si2O7 environmental barrier coatings corroded by a silicate melt

• Published in: Corrosion science 2024-09, Vol.238, p.112378, Article 112378
• Main Authors: Costa, Gustavo, Presby, Michael J., Almansour, Amjad S., Webster, Rebeka I., Lee, Kang N.
• Format: Article
• Language: English
• Subjects: CMAS; Corrosion; EBCs; Mechanical properties; Thermochemistry
• ISSN: 0010-938X
• DOI: 10.1016/j.corsci.2024.112378

The chemical and mechanical properties of plasma-spray-modified Yb2Si2O7 environmental barrier coatings were investigated after corrosion by a low silicate melt surface concentration at 1315 °C for 1 h. X-ray diffraction, simultaneuos thermal analysis, electron probe microanalysis, electron microscopy, and nanoindentation testing were used to probe coating samples. Garnet was favored to form over apatite in coatings with alumina content higher than 1–2 mol%. Garnet formation arrested corrosion through removal of the melt components. The corroded and heat-treated coatings exhibited a higher overall percentage of enhancement to the Young’s modulus and hardness results when compared to as-deposited coating samples. •Chemical and physical properties of modified ytterbium disilicate environmental barrier coatings were investigated after corrosion by a CMAS melt.•Garnet was favored to crystallize over apatite in EBCs with alumina contents higher than 1–2 mol%.•Garnet crystallization arrested corrosion through removal of the melt components.•The corroded coatings showed a greater overall increase in the Young’s modulus and hardness when compared with uncorroded coatings.