Effects of Syngas Particulate Fly Ash Deposition on the Mechanical Properties of Thermal Barrier Coatings on Simulated Film-Cooled Turbine Vane Components

Kevin Luo¹, Andrew C. Nix¹, Bruce S. Kang², Dumbi A. Otunyo²

¹Center for Alternative Fuels, Engines and Emissions, Department of Mechanical and Aerospace Engineering, Morgantown, USA.
²Department of Mechanical and Aerospace Engineering, Morgantown, USA.

DOI: 10.4236/ijcce.2014.34006                

Abstract

Research is being conducted to study the effects of particulate deposition from contaminants in coal synthesis gas (syngas) on the mechanical properties of thermal barrier coatings (TBC) employed on integrated gasification combined cycle (IGCC) turbine hot section airfoils. West Virginia University (WVU) had been working with US Department of Energy, National Energy Technology Laboratory (NETL) to simulate deposition on the pressure side of an IGCC turbine first stage vane. To model the deposition, coal fly ash was injected into the flow of a combustor facility and deposited onto TBC coated, angled film-cooled test articles in a high pressure (approximately 4 atm) and a high temperature (1560 K) environment. To investigate the interaction between the deposition and the TBC, a load-based multiple-partial unloading micro-indentation technique was used to quantitatively evaluate the mechanical properties of materials. The indentation results showed the Young’s Modulus of the ceramic top coat was higher in areas with deposition formation due to the penetration of the fly ash. This corresponds with the reduction of strain tolerance of the 7% yttria-stabilized zirconia (7YSZ) coatings.

Keywords

IGCC Gas Turbine Thermal Barrier Coatings, Coal Syngas, Fly Ash Deposition, Micro-Indentation, Strain Tolerance

Conflicts of Interest

The authors declare no conflicts of interest.

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