Understanding Environmental Barrier Coating Lifetimes and Performance for Industrial Gas Turbines

Journal Article · 15 October 2024 · Journal of Engineering for Gas Turbines and Power

DOI: https://doi.org/10.1115/1.4066349 · OSTI ID:2448174

Ridley, M. J.  ^[1]; Lance, M. J. ^[1]; Aguirre, T. G. ^[1]; Kane, K. A. ^[2]; Pint, B. A.  ^[1]

---

1. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
2. Johns Hopkins Univ., Laurel, MD (United States). Applied Physics Laboratory (APL)

Hydrogen or hydrogen blend fuels are expected to replace natural gas in land-based industrial gas turbines (IGTs) to support a greener power economy. Silicon carbide (SiC) base ceramic matrix composites (CMCs) are considered for replacement of Ni-based superalloys to facilitate future efficiency improvements. SiC CMCs require environmental barrier coatings (EBCs) to mitigate volatilization from high-temperature steam, thus making the EBC lifetime critical information for identifying CMC component lifetimes. Here, the goal of this project is to determine the maximum bond coating temperature underneath the EBC for achieving an IGT component lifetime goal of 25,000 h, which is far greater than current CMC component lifetime requirements for aeroturbine applications. To provide data for the lifetime model, laboratory testing used atmospheric plasma-sprayed rare-earth silicate EBCs on monolithic SiC substrates with an intermediate Si bond coating. Specimens exposed to 1-h thermal cycles in flowing air–steam environments and reaction kinetics were assessed from 700 °C to 1350 °C by measuring the thickness of the thermally grown silica scales. The silica growth and phase transformation appear critical in predicting EBC lifetime and several strategies have been explored to reduce the oxide growth rate and improve EBC durability at elevated temperatures. Advanced characterization using Raman spectroscopy has helped clarify this system.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy and Carbon Management (FECM)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 2448174
• Journal Information: Journal of Engineering for Gas Turbines and Power, Journal Name: Journal of Engineering for Gas Turbines and Power Journal Issue: 3 Vol. 147; ISSN 0742-4795
• Publisher: ASMECopyright Statement
• Country of Publication: United States
• Language: English