Corrosion behavior of YxYb(2_x)Si2O7 environmental barrier coating materials against molten calcium-magnesium-aluminosilicate (CMAS) at 1475 C

The molten calcium-magnesium-aluminosilicate (CMAS) corrosion resistance of a series of YxYb(2_x)Si2O7 (x = 0.3, 0.5, 0.8, 1.0) environmental barrier coating (EBC) materials were systematically investigated at 1475 degrees C. The results have shown that the precipitate apatite Ca2(Y/Yb)8(SiO4)6O2 formed after CMAS corrosion of YxYb(2_x)Si2O7 pellets. The reactivity of YxYb(2_x)Si2O7 pellets and CMAS increased with the increase of Y3+/ Yb3+ ratio, leading to the thickest reaction layer formed in Y1.0Yb1.0Si2O7. Furthermore, "blister" cracks were not found at the zone of uncorroded YxYb(2_x)Si2O7 pellets. It demonstrated that the YxYb(2_x)Si2O7 materials have excellent CMAS corrosion resistance, which can serve as promising candidates for EBC against CMAS corrosion.