Corrosion of RE2Si2O7 (RE=Y, Yb, and Lu) environmental barrier coating materials by molten calcium-magnesium-alumino-silicate glass at high temperatures

In situ observation of environmental barrier coating against calcium–magnesium–alumina–silicate attack at elevated temperature

“…Krämer et al investigated the thermochemical interaction between a Gd 2 Zr 2 O 7 thermal barrier coating and a CMAS melt with a melting point of ~1240°C, and they have found that a dense, fine‐grained, ~6 um thick reaction layer formed after 4 h of isothermal exposure to 1300°C 14 . Tian et al investigated the corrosion resistance of three EBC candidates to CMAS melts at 1300℃ and 1500℃ for 50 h and found that the grain boundary engineering was critically demanded to optimize CMAS corrosion at high temperature 15 . Song et al has conducted a series study, which focused on the wetting and spreading of molten ash droplets on the engine component surfaces with thermal barrier coating 16–18 and found that both viscosity and microstructural evolution are key controls on the attainment of equilibrium in the wetting of molten ash droplets 19 …”

“…14 Tian et al investigated the corrosion resistance of three EBC candidates to CMAS melts at 1300℃ and 1500℃ for 50 h and found that the grain boundary engineering was critically demanded to optimize CMAS corrosion at high temperature. 15 Song et al has conducted a series study, which focused on the wetting and spreading of molten ash droplets on the engine component surfaces with thermal barrier coating [16][17][18] and found that both viscosity and microstructural evolution are key controls on the attainment of equilibrium in the wetting of molten ash droplets. 19 Here, an in situ method has been employed to study the erosion effect of CMAS phase to EBC at elevated temperature, which were 1200℃, 1300℃, and 1500℃, respectively.…”

Rare-earth pyrosilicate solid-solution environmental-barrier coating ceramics for resistance against attack by molten calcia–magnesia–aluminosilicate (CMAS) glass

“…Thus, at the Lewis acid-base chemistry level, the reactivity between a crystalline oxide ceramic and an oxide glass is expected to decrease with the decreasing difference between their OBs [16]. Based on this criterion, rare-earth pyrosilicates (RE = rare earth, RE 2 Si 2 O 7 ) such as γ-Y 2 Si 2 O 7 and β-Yb 2 Si 2 O 7 have been identified as promising CMAS-resistant EBC ceramics [16], which have also been studied by others [15,[17][18][19][20][21][22][23][24][25][26][27]. It should be emphasized that the OB difference analysis provides a rough screening criterion based purely on chemical considerations.…”

“…Although there have been several studies focused on the interactions between RE pyrosilicates and CMAS [15,[17][18][19][20][21][22][23][24][25][26][27], there is little known about CMAS interactions with pyrosilicate solid solutions. Fig.…”

Oxidation Performance of Ytterbium Disilicate/Silicon Environmental Barrier Coating via Optimized Air Plasma Spraying

“…It can be divided into four stages for EBC systems. Currently, researchers mainly focus on rare earth silicate systems [10] and move towards material systems of multi-layered thermal barrier coupled with environmental barrier [11]. The main preparation methods of EBCs include air plasma spraying [12] (APS), electron beam physical vapor deposition [13] (EB-PVD), plasma spraying physical vapor deposition [14] (PS-PVD), ultra-low pressure plasma spraying [15] (VLPPS), etc.…”