Corrosion behavior of volcanic ash and calcium magnesium aluminosilicate on Yb₂SiO₅ environmental barrier coatings

High-temperature corrosion behavior of volcanic ash and artificial calcium-magnesium-aluminosilicate (CMAS) on sintered ytterbium monosilicate (Yb₂SiO₅), and the corrosion resistance of Yb₂SiO₅ as an environmental barrier coating, are investigated. Dense sintered Yb₂SiO₅ specimens were prepared using the spark plasma sintering method at 1400°C for 10 min. These specimens were subjected to a hot corrosive environment of molten Iceland volcanic ash and CMAS at 1400°C for 2, 12, and 48 h. Different corrosion phenomena, i.e., continuous reaction with CMAS and weak reaction with the volcanic ash, were observed. From the results of in-situ high temperature X-ray diffraction measurement and scanning electron microscope-energy dispersive X-ray spectrometry studies, Yb₂SiO₅ exhibits excellent resistance to volcanic ash but lacks resistance to CMAS attack.