Water vapor corrosion behaviors of plasma sprayed ytterbium silicate coatings

The excellent protection effects of silicon/ytterbium silicate bilayer environmental barrier coatings on SiCf/SiC composites

“…With an increase of the corrosion time, the phase composition of topcoat barely changed, suggesting that current topcoat shows excellent phase stability in current corrosive environment. However, it is worth pointing out that a new phase of Yb 3 Al 5 O 12 can be detected after 160 and 200‐h corrosion 15 . This is attributed to the usage of alumina tube, which is also reactive with water vapor to produce gaseous Al(OH) 3 at elevated temperatures, and the following reaction might take place according to Ref.…”

“…However, it is worth pointing out that a new phase of Yb 3 Al 5 O 12 can be detected after 160 and 200h corrosion. 15 This is attributed to the usage of alumina tube, which is also reactive with water vapor to produce gaseous Al(OH) 3 at elevated temperatures, and the following reaction might take place according to Ref. [16]:…”

Significantly improved corrosion resistance of high‐entropy rare‐earth silicate multiphase ceramics against molten CMAS

“…Rare‐earth (RE) silicates are one of the most promising environmental barrier coating (EBC) materials that are used to protect SiC‐based ceramic matrix composite (SiC‐CMC) components in the hot‐section of new gas‐turbine engines used for aircraft propulsion 1–5 . This is because the RE silicates not only have good chemical compatibility and matching coefficient of thermal expansion (CTE) with SiC‐CMCs 6,7 but also exhibit relatively good corrosion resistance in water vapor and molten calcium–magnesium–aluminosilicate (CMAS) at low temperature (≤1300°C) 8–11 . However, the ability to resist molten CMAS corrosion at high temperature (≥1500°C) will be a challenge for single‐component RE monosilicates (RE 2 SiO 5 ) and disilicates (RE 2 Si 2 O 7 ) 12 .…”

“…[1][2][3][4][5] This is because the RE silicates not only have good chemical compatibility and matching coefficient of thermal expansion (CTE) with SiC-CMCs 6,7 but also exhibit relatively good corrosion resistance in water vapor and molten calciummagnesium-aluminosilicate (CMAS) at low temperature (≤1300 • C). [8][9][10][11] However, the ability to resist molten CMAS corrosion at high temperature (≥1500 • C) will be a chal-Yuxuan He and Xu Wang contributed equally to this work and should be considered co-first authors. lenge for single-component RE monosilicates (RE 2 SiO 5 ) and disilicates (RE 2 Si 2 O 7 ).…”

Corrosion behavior and mechanism of ytterbium silicates environmental barrier coatings subjected to thermal cycling in water vapor

“…25 Our previous work found that the Yb 2 SiO 5 coating possessed excellent water vapor corrosion resistance. 26 Moreover, the Yb 2 Si 2 O 7 coating could effectively improve the crack propagation resistance, and the Yb 2 SiO 5 /Yb 2 Si 2 O 7 /Si EBCs exhibited good thermal shock resistance, which was expected to prolong the service life of the rare-earth silicate EBCs under high-temperature water vapor environment. 27 However, the water vapor corrosion behaviors of the Yb 2 SiO 5 /Yb 2 Si 2 O 7 /Si EBCs were not investigated.…”