The influence of bondcoat and topcoat mechanical properties on stress development in thermal barrier coating systems

Busso, Esteban P.; Qian, Z.Q.; Taylor, M.P.; Evans, Hugh E.

doi:10.1016/j.actamat.2009.01.017

Cited by 135 publications

(55 citation statements)

References 14 publications

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“…These results indicate that the granule morphology is essential to the TBC microstructure. As it is reported that TBC with a porosity of 10∼20% offers an advantage in the application of TBCs [3], the spray granules in this study are desirable for the gas turbine applications.…”

Section: Resultsmentioning

confidence: 99%

“…One critical problem of the failures of TBCs is spallation or delamination of the coating layers due to mismatch of thermal expansion between the coating and the bond coat material. However, mechanical resistance such as wear or strain tolerance is the other required issue for resistance of spallation [3,[10][11][12].…”

Section: Introductionmentioning

confidence: 99%

“…The operating temperature tends to increase to over 1300 ∘ C to enhance the energy efficiency of a gas turbine system, which drives a new cooling system and an increase of TBC thickness and adjusting microstructures of the coating layer [3].…”

Section: Introductionmentioning

confidence: 99%

“…In order to decrease the thermal mismatch and to improve the adhesion between the coating and the substrate, a bond coat, 75∼200 m of thickness, is usually deposited on the substrate, and then topcoat is finally applied [3,4].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Evaluation of Thermal Durability of Thermal Barrier Coating and Change in Mechanical Behavior

Lee¹,

Kang²,

Lee³

et al. 2017

J. Korean Ceram. Soc

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The effect of starting granules on the indentation properties of air plasma sprayed thermal barrier coatings (TBCs) is investigated in this paper. Various kinds of spray-dried granules are prepared from different processing conditions, especially varying solvent and dispersant, showing a deformed hollow-typed and a filled spherical-typed granule. The similar coating thicknesses are prepared by adjusting process parameters during air plasma spray. All XRD peaks in phase analysis are tetragonal and cubic phases without any monoclinic phase after the starting granules were heat-treated. A relatively porous microstructure of the coating layer could be obtained from the monodisperse granules, while a relatively dense microstructure resulted from the hollow-typed granules. The morphology and distribution of the granules crucially affect the microstructure of thermal barrier coatings and thus have influences on indentation properties such as indentation stress-strain curves, contact damage, and hardness. The implication concerning microstructure design of TBCs for gas turbine applications is considered.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Evaluation of Thermal Durability of Thermal Barrier Coating and Change in Mechanical Behavior

Lee¹,

Kang²,

Lee³

et al. 2017

J. Korean Ceram. Soc

View full text Add to dashboard Cite

show abstract

“…This can be done with finite element simulations, which allow to simulate how thermal cycling and TGO growth affect the stress state in a thermal barrier coating (Ref 3,4,5,6,7).…”

Section: Introductionmentioning

confidence: 99%

A Guide to Finite Element Simulations of Thermal Barrier Coatings

Bäker

Seiler

2017

J Therm Spray Tech

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To understand the stress evolution and failure mechanisms of thermal barrier coatings (TBCs), finite element simulations are an invaluable tool. Simulations are especially useful to unwrap complex interactions of different phenomena at high temperature, including creep, sintering, diffusion, and oxidation. However, the correct setup and evaluation of a finite element model for this problem are difficult. This article reviews critical issues in modelling TBC systems. Some of the most important aspects are as follows: (a) stresses in 3D simulations may differ considerably from 2D models; (b) the interface shape strongly affects the stresses and using an idealized geometry may underestimate stresses; (c) crack propagation requires simulating sufficiently large regions to correctly capture stress redistribution; (d) a correct description of the material behaviour (visco-plasticity, TGO growth, sintering) is crucial in determining the stress state. The article discusses these and other issues in detail and provides guidelines on the choice of model parameters, boundary conditions, etc. The paper also points out open questions in modelling TBC systems and discusses aspects of verification and validation.

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Thermomechanical Fatigue Life of TBCS—Experimental and Modeling Aspects

Sjöström

Brodin

2010

Advanced Ceramic Coatings and Interfaces V

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The fatigue life of APS TBC under TMF loading has been studied. Failure can be by spallation from convex surfaces, spallation from flat or nearly flat surfaces and spallation from sharp edges. The damage evolution leading to final failure has been studied experimentally, and based on the experimental observations, a fracture-mechanical model for the formation and growth of cracks in or near the thermally grown oxide and for the final failure of the TBC has been set up. INTRODUCTIONThe concept of thermal barrier coatings (TBCs) is well-known among gas-turbine designers. The fundamental idea of a TBC is that an insulating ceramic top coat (TC) is used for thermal protection of components which are exposed to hot gas (e.g., combustor linings, turbine guide vanes and turbine blades). Between the substrate and the TC there is generally a bond coat (BC), which is a metallic alloy with double purposes. On one hand, it improves the adhesion between the substrate and the TC, and on the other hand it protects the substrate from high-temperature oxidation by itself oxidising into oxides with less unfavourable properties than oxides forming directly on the substrate would have had.Depending on the application method there exist two main types of TBC, namely air-plasmasprayed (APS) and electron-beam physical-vapour-deposited (EB-PVD). EB-PVD TBCs are mainly used in aeroengine turbine vanes and blades, while larger components, such as burner liners and turbine vanes and blades in stationary gas-turbine engines mainly use APS TBC. The TMF properties are quite different for the two types, and this article is therefore limited to the analysis of APS TBC.

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The influence of bondcoat and topcoat mechanical properties on stress development in thermal barrier coating systems

Cited by 135 publications

References 14 publications

Evaluation of Thermal Durability of Thermal Barrier Coating and Change in Mechanical Behavior

Evaluation of Thermal Durability of Thermal Barrier Coating and Change in Mechanical Behavior

A Guide to Finite Element Simulations of Thermal Barrier Coatings

Thermomechanical Fatigue Life of TBCS—Experimental and Modeling Aspects

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