Advanced thermal/environmental barrier coatings of high-entropy rare earth disilicates tuned by strong anharmonicity of Eu2Si2O7
- National Energy Technology Laboratory (NETL), Albany, OR (United States); NETL Support Contractor, Albany, OR (United States)
- National Energy Technology Laboratory (NETL), Albany, OR (United States)
Advancing thermal/environmental barrier coating (TEBC) materials with integrated thermal-mechanical functions is paramount for safeguarding SiC-based ceramic matrix composites (CMCs) in high-efficiency gas turbines. Herein, we employ a synergistic approach, combining density functional theory (DFT) methods and combinatorial chemistry techniques, to design high-performance and low-cost RE2Si2O7 (RE = rare earth elements) TEBC materials tailored for enhanced compatibility with SiC-based CMCs. Expanding on phase stability of alloying pure RE2Si2O7, the investigation extends to the mechanical and thermal properties of solid solution systems, including Er1/2Y3/4Yb3/4Si2O7, Gd1/4Er1/4Y3/4Yb3/4Si2O7, and Eu1/4Er1/4Y3/4Yb3/4Si2O7. The solid solution systems exhibit a major reduction in lattice thermal conductivity relative to their pure counterparts, achieving ultralow values of 0.25 to 0.39 W m−1 K−1 at 1500 K. Furthermore, the coefficients of thermal expansion (CTE) of these solid solutions are precisely tuned within the desired range for SiC (4.4 to 5.5 × 10−6 K−1), while maintaining good mechanical properties. Here, in particular, the addition of Eu2Si2O7 demonstrates to be an important variable to the tuning of CTE and lattice thermal conductivity by leveraging its strong anharmonicity, presenting a pioneering avenue for fine-tuning material properties. In summary, this research not only identifies promising TEBC materials with superior thermal properties, but also introduces a valuable computational material design methodology for the rapid discovery of complex materials for harsh environments.
- Research Organization:
- National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF); USDOE Office of Fossil Energy and Carbon Management (FECM); USDOE Office of Energy Efficiency and Renewable Energy (EERE); National Energy Research Scientific Computing Center (NERSC)
- Grant/Contract Number:
- AC02-05CH11231
- OSTI ID:
- 2570552
- Journal Information:
- Journal of Materials Chemistry C, Journal Name: Journal of Materials Chemistry C Journal Issue: 45 Vol. 12; ISSN 2050-7534; ISSN 2050-7526
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Influence of cation species on thermal expansion of Y2Si2O7–Gd2Si2O7 solid solutions
Solid solubility of Yb{sub 2}Si{sub 2}O{sub 7} in {beta}-, {gamma}- and {delta}-Y{sub 2}Si{sub 2}O{sub 7}