Estimation of spallation life of thermal barrier coating of gas turbine blade by thermal fatigue test

Shin, In Hwan; Koo, Jae-Mean; Seok, Chang-Sung; Yang, Sung-Ho; Lee, Tack-Woon; Kim, Bum Soo

doi:10.1016/j.surfcoat.2011.02.068

Cited by 22 publications

(11 citation statements)

References 9 publications

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“…Thermal cycling is known to be a major contributing factor to TBC life. One study attempted to identify the effects of temperature and thermal cycling on TBC delamination (Shin, et al, 2011).…”

Section: Thermal Barrier Coatingsmentioning

confidence: 99%

Geometric Effects of Thermal Barrier Coating Damage on Turbine Blade Temperatures

Colón

Ricklick

Nagy³

et al. 2019

Volume 2D: Turbomachinery

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Thermal barrier coatings (TBC) found on turbine blades are a key element in the performance and reliability of modern gas turbines. TBC reduces the heat transfer into turbine blades by introducing an additional surface thermal resistance; consequently allowing for higher gas temperatures. During the service life of the blades, the TBC surface may be damaged due to manufacturing imperfections, handling damage, service spalling, or service impact damage, producing chips in the coating. While an increase in aerofoil temperature is expected, it is unknown to what degree the blade will be affected and what parameters of the chip shape affect this result. During routine inspections, the severity of the chipping will often fall to the discretion of the inspecting engineer. Without a quantitative understanding of the flow and heat transfer around these chips, there is potential for premature removal or possible blade failure if left to operate. The goal of this preliminary study is to identify the major driving parameters that lead to the increase in metal temperature when TBC is damaged, such that more quantitative estimates of blade life and refurbishing needs can be made. A two-dimensional computational Conjugate Heat Transfer model was developed; fully resolving the hot gas path and TBC, bond-coat, and super alloy solids. Representative convective conditions were applied to the cold side to emulate the characteristics of a cooled turbine blade. The hot gas path properties included an inlet temperature of 1600 K with varying Mach numbers of 0.30, 0.59, and 0.80 and Reynolds number of 5.1×105, 7.0×105, and 9.0×105 as referenced from the leading edge of the model. The cold side was given a coolant temperature of 750 K and a heat transfer coefficient of 1500 W/m2*K. The assigned thermal conductivities of the TBC, bond-coat, and metal alloys were 0.7 W/m*K, 7.0 W/m*K, and 11.0 W/m*K, respectively, and layer thicknesses of 0.50 mm, 0.25 mm, and 1.50 mm, respectively. A flat plate model without the presence of the chip was first evaluated to provide a basis of validation by comparison to existing correlations. Comparing heat transfer coefficients, the flat plate model matched within uncertainty to the Chilton-Colburn analogy. In addition, flat plate results captured the boundary layer thickness when compared with Prandtl’s 1/7th power-law. A chip was then introduced into the model, varying the chip width and the edge geometry. The most sensitive driving parameters were identified to be the chip width and Mach number. In cases where the chip width reached 16 times the TBC thickness, temperatures increased by almost 30% when compared to the undamaged equivalents. Additionally, increasing the Mach number of the incoming flow also increased metal temperatures. While the Reynolds number based on the leading edge of the model was deemed negligible, the Reynolds number based on the chip width was found to have a noticeable impact on the blade temperature. In conclusion, this study found that chip edge geometry was a negligible factor, while the Mach number, chip width, and Reynolds number based on the chip width had a significant effect on the total metal temperature.

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Section: Thermal Barrier Coatingsmentioning

confidence: 99%

Geometric Effects of Thermal Barrier Coating Damage on Turbine Blade Temperatures

Colón

Ricklick

Nagy³

et al. 2019

Volume 2D: Turbomachinery

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“…As the piston is the most important part of the combustion chamber of the engine, it is necessary to study the heat transfer of the piston to ensure the safe and reliable operation of the engine. Ceramic thermal barrier coating (TBC) has been widely used in blades of aircraft engines and gas turbines to protect the superalloy parts of the blades from high temperature and oxidation, thereby prolonging the service life of the engine [4][5][6][7]. The NiCrAlY coating is widely used in the bonding layer between the thermal insulation coating and the metal substrate because the coefficient of thermal expansion is between the metal substrate and the ceramic heat insulation layer [8].…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Research on Thermal Insulation Performance of Marine Diesel Engine Piston Based on YSZ Thermal Barrier Coating

et al. 2021

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Although YSZ ceramic coating has been used in the field of aeroengines for a long time to protect blades from high temperature erosion, its application on marine engines is still very rare. In this study, YSZ powder was sprayed onto the upper surface of the Al-Si alloy piston by atmospheric plasma spraying. The piston with or without ceramic coatings was applied to the diesel engine bench, and the ship propulsion characteristics test was carried out to study the effect of the coating on the performance of the diesel engine when the ship was sailing. The temperature field results show that under 25% load, the temperature of the top surface of the coated piston is about 30.91 °C higher than that of the conventional piston. The increase in the temperature of the combustion chamber is conducive to better combustion of the fuel in the cylinder of the diesel engine. Therefore, when the marine diesel engine is tested for propulsion characteristics, the thermal efficiency is increased by 5% under the condition of 25% load.

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“…TBCs are crucial in gas turbine engines to provide thermal insulation to the turbine components that are exposed to heat thereby allowing them to be operated at higher temperatures and subsequently higher efficiencies. The TBC is made up of three layers which are the bond coat, the top coat made of ceramic and a thermally grown oxide (TGO) which forms between the two coats [5]. Research has shown that the NiAl powder that is sprayed onto the nickel-based superalloy forms the β-NiAl layer which is also the bond coat of the TBC which will in turn oxidize at elevated temperatures and forms the TGO layer [4].…”

Section: Introductionmentioning

confidence: 99%

Oxidation Behavior of NiAl Produced by Gel Combustion Synthesis

Gonsalvez

Manap²,

Afandi³

et al. 2016

KEM

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This paper presents the results of a study of the oxidation behavior of NiAl produced by gel combustion synthesis calcined at two different temperatures. The objective is to compare the oxide growth rates, oxide scale composition, morphology and elemental composition of the sample powder subjected to isothermal oxidation and calcined at 1050 °C and 1300 °C for 1, 2, 4 and 10 hours by means of mass gain measurements, X-ray diffraction (XRD), field emission scanning electron microsocopy (FESEM) and energy-dispersive spectrometry (EDX) in order to investigate the reliability of the gel combustion synthesis method and evaluate the effect of calcination temperature on the oxidation behaviour of the powder. It was found that for the sample calcined at 1300°C the sample was made up mainly of metastable and stable alumina before oxidation and stable alpha alumina after oxidation whereas for the powder calcined at 1050°C the sample was mainly composed of detrimental mixed oxides before and after oxidation. Overall findings indicate that the oxidation behavior of the powder calcined at 1300°C is more protective compared to the powder calcined at 1050°C.

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Estimation of spallation life of thermal barrier coating of gas turbine blade by thermal fatigue test

Cited by 22 publications

References 9 publications

Geometric Effects of Thermal Barrier Coating Damage on Turbine Blade Temperatures

Geometric Effects of Thermal Barrier Coating Damage on Turbine Blade Temperatures

Numerical and Experimental Research on Thermal Insulation Performance of Marine Diesel Engine Piston Based on YSZ Thermal Barrier Coating

Oxidation Behavior of NiAl Produced by Gel Combustion Synthesis

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