Reaction behaviors and mechanisms of tri-layer Yb2SiO5/Yb2Si2O7/Si environmental barrier coatings with molten calcium-magnesium-alumino-silicate

Li, Pingping; Zhong, Xin; Niu, Yaran; Huang, Liping; Li, Hong; Fan, Dong; Li, Qilian; Zheng, Xiaofeng; Sun, Jianfei

doi:10.1016/j.corsci.2021.110069

Cited by 37 publications

(18 citation statements)

References 35 publications

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“…Rare earth silicates (RE2SiO5 and RE2Si2O7) are known as the preferred environmental barrier coating materials [9,10]. The thermal expansion coefficient (CTE) of β-type and γ-type pyrosilicate is about 4.0-5.4 × 10 -6 k -1 [11], which is very close to that of CMCs and Si bond layers, whose damage tolerance is excellent [12].…”

Section: Introductionmentioning

confidence: 92%

Influence of average radii of RE³⁺ions on phase structures and thermal expansion coefficients of high-entropy pyrosilicates

Chen¹,

Lin²,

Zheng³

et al. 2023

Journal of Advanced Ceramics

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High-entropy pyrosilicate element selection is relatively blind, and the thermal expansion 2 coefficient of traditional β-type pyrosilicate is not adjustable, making it difficult to meet the requirements of various types of ceramic matrix composites. The following study aimed to develop a universal rule for high-entropy pyrosilicate element selection and to achieve directional control of the thermal expansion coefficient of high-entropy pyrosilicate. The current study investigates a highentropy design method for obtaining pyrosilicates with stable β-phase and γ-phase by introducing various rare earth (RE) cations. The solid-phase method was used to create twelve different types of high-entropy pyrosilicates with 4-6 components. The high-entropy pyrosilicates gradually transformed from β-phase to γ-phase with an increase in the average radius of RE 3+ ions. The nine pyrosilicates with a small average radius of RE 3+ ions preserve β-phase or γ-phase stability at room temperature to the maximum of 1400 °C. The intrinsic relationship between the thermal expansion coefficient, phase structure, and RE-O bond length has also been found. This study provides the theoretical background for designing high-entropy pyrosilicates from the perspective of the average radius of RE 3+ ions. The theoretical guidance makes it easier to synthesize high-entropy pyrosilicates with stable β-phase or γ-phase for use in environmental barrier coatings. The thermal expansion coefficient of γ-type high-entropy pyrosilicate can be altered through component design to match various types of ceramic matrix composites.

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Section: Introductionmentioning

confidence: 92%

Influence of average radii of RE³⁺ions on phase structures and thermal expansion coefficients of high-entropy pyrosilicates

Chen¹,

Lin²,

Zheng³

et al. 2023

Journal of Advanced Ceramics

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“…They display superior high-temperature durability and corrosion resistance in comparison to the first generation (mullite and yttria-stabilized zirconia) and the second generation (1-xBaO•xSrO•Al2O3•2SiO2, 0 ≤ x ≤1) T/EBCs [12,14,[16][17][18]. In addition, rare-earth silicates possess the double advantage of chemical stability together with rather low thermal conductivity [7,[19][20][21][22]. Nevertheless, they are still confronted with the issue of water vapor corrosion owing to the formation of volatile Si(OH)4.…”

Section: Introductionmentioning

confidence: 99%

Xenotime-type high-entropy (Dy_1/7Ho_1/7Er_1/7Tm_1/7Yb_1/7Lu_1/7Y_1/7)PO₄: A promising thermal/environmental barrier coating material for SiC_f/SiC ceramic matrix composites

Zhang¹,

Duan²,

Xie³

et al. 2023

Journal of Advanced Ceramics

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Rare-earth phosphates (REPO4) are regarded as one of the promising thermal/environmental barrier coating (T/EBC) materials for SiCf/SiC ceramic matrix composites (SiC-CMCs) owing to their excellent resistance to water vapor and CaO-MgO-Al2O3-SiO2 (CMAS). Nevertheless, relatively high thermal conductivity of REPO4 becomes the bottleneck for their practical application. In this work, novel xenotime-type high entropy (Dy1/7Ho1/7 Er1/7Tm1/7Yb1/7Lu1/7Y1/7)PO4 (HE (7RE1/7)PO4) has been designed and synthesized for the first time to solve this issue. HE (7RE1/7)PO4 with a homogeneous rare-earth element distribution exhibits high thermal stability up to 1750 °C and good chemical compatibility with SiO2 up to 1400 °C. In addition, the thermal expansion coefficient (TEC) of HE (7RE1/7)PO4(5.96 × 10 -6 /°C at room temperature to 900 °C) is close to that of SiC-CMCs. What's more, the thermal conductivity of HE (7RE1/7)PO4 (from 4.38 W•m -1 K -1 at 100 °C to 2.25 W•m -1 K -1 at 1300 °C) is significantly decreased compared to those of single-component REPO4 with the minimum value ranging from 9.90 to 4.76 W•m -1 •K -1 . These results suggest that HE (7RE1/7)PO4 has the potential to be applied as T/EBC material for SiC-CMCs in the future.

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“…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 .…”

Section: Introductionmentioning

confidence: 99%

“…[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 ).…”

Section: Introductionmentioning

confidence: 99%

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

Wang

et al. 2023

J Am Ceram Soc.

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To improve the ability of rare‐earth (RE) silicates to resist molten calcium–magnesium–aluminosilicate (CMAS) at high temperature, a novel high‐entropy (4RE0.25)2Si2O7/(4RE0.25)2SiO5 (RE = Y, Yb, Er, and Sc) multiphase ceramic was prepared by a two‐step process. During sintering, (4RE0.25)2SiO5 can react with SiO2 at the grain boundaries of (4RE0.25)2Si2O7, which can not only purify the grain boundary but also promote the growth of the original (4RE0.25)2Si2O7 grains, thereby significantly improving the ability to resist molten CMAS corrosion at high temperature. After corroding at 1500°C for 48 h, the reaction layer of the multiphase ceramic was only 55 μm thick. Our results confirm that the high‐entropy RE silicate multiphase ceramics represent an effective way to improve the ability to resist molten CMAS corrosion at high temperature.

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Reaction behaviors and mechanisms of tri-layer Yb2SiO5/Yb2Si2O7/Si environmental barrier coatings with molten calcium-magnesium-alumino-silicate

Cited by 37 publications

References 35 publications

Influence of average radii of RE³⁺ions on phase structures and thermal expansion coefficients of high-entropy pyrosilicates

Influence of average radii of RE³⁺ions on phase structures and thermal expansion coefficients of high-entropy pyrosilicates

Xenotime-type high-entropy (Dy_1/7Ho_1/7Er_1/7Tm_1/7Yb_1/7Lu_1/7Y_1/7)PO₄: A promising thermal/environmental barrier coating material for SiC_f/SiC ceramic matrix composites

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

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Reaction behaviors and mechanisms of tri-layer Yb2SiO5/Yb2Si2O7/Si environmental barrier coatings with molten calcium-magnesium-alumino-silicate

Cited by 37 publications

References 35 publications

Influence of average radii of RE3+ions on phase structures and thermal expansion coefficients of high-entropy pyrosilicates

Influence of average radii of RE3+ions on phase structures and thermal expansion coefficients of high-entropy pyrosilicates

Xenotime-type high-entropy (Dy1/7Ho1/7Er1/7Tm1/7Yb1/7Lu1/7Y1/7)PO4: A promising thermal/environmental barrier coating material for SiCf/SiC ceramic matrix composites

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

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Influence of average radii of RE³⁺ions on phase structures and thermal expansion coefficients of high-entropy pyrosilicates

Influence of average radii of RE³⁺ions on phase structures and thermal expansion coefficients of high-entropy pyrosilicates

Xenotime-type high-entropy (Dy_1/7Ho_1/7Er_1/7Tm_1/7Yb_1/7Lu_1/7Y_1/7)PO₄: A promising thermal/environmental barrier coating material for SiC_f/SiC ceramic matrix composites