Segmented Thermal Barrier Coatings on Turbine Blades and Diesel Engine Components

1994 ◽  
pp. 705-716 ◽  
Author(s):  
S. Sturlese ◽  
L. Bertamini
Keyword(s):  
Diesel Engine ◽  
Thermal Barrier Coatings ◽  
Turbine Blades ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Engine Components

scholarly journals Thermomechanical fatigue characterization of zirconia (8%Y2O3-ZrO2) and mullite thermal barrier coatings on diesel engine components: Effect of coatings on engine performance

2000 ◽  
Vol 214 (5) ◽  
pp. 729-742 ◽  
Author(s):  
P Ramaswamy ◽  
S Seetharamu ◽  
K B R Verma ◽  
N Raman ◽  
K J Rao
Keyword(s):  
Diesel Engine ◽  
Thermal Barrier Coatings ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
X Ray ◽  
Piston Head ◽  
Mullite Coatings ◽  
Engine Components

8%Y2O3-stabilized zirconia (8YPSZ) and mullite (3Al2O3·2SiO2) powders, which were made plasma sprayable by using an organic binder (polyvinyl alcohol), have been plasma spray coated on to the piston head, valves and cylinder head of a 3.8kW single-cylinder diesel engine, previously coated with Ni-Cr-Al-Y bond coat. The engine with components coated with 250 μm thick 8YPSZ and 1 mm thick mullite thermal barrier coatings has been evaluated for fuel efficiency and for endurance during 500 h long rigorous tests. Improved fuel efficiency was shown by the engine with coated components and the results are discussed. The coatings and the coated components have also been examined for phases, microstructure and chemical composition by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Mullite coatings were found to exhibit increased resistance to microcracking compared with 8YPSZ during the 500 h endurance test.

scholarly journals Analysis of the energetic/environmental performances of gas turbine plant: Effect of thermal barrier coatings and mass of cooling air

2009 ◽  
Vol 13 (1) ◽  
pp. 147-164 ◽  
Author(s):  
Ion Ion ◽  
Anibal Portinha ◽  
Jorge Martins ◽  
Vasco Teixeira ◽  
Joaquim Carneiro
Keyword(s):  
Thermal Conductivity ◽  
Gas Turbine ◽  
Thermal Barrier Coatings ◽  
Turbine Blades ◽  
Heat Transfer Analysis ◽  
Thermal Barrier ◽  
Inlet Temperature ◽  
Barrier Coatings ◽  
Cooling Air Flow ◽  
Cooling Air

Zirconia stabilized with 8 wt.% Y2O3 is the most common material to be applied in thermal barrier coatings owing to its excellent properties: low thermal conductivity, high toughness and thermal expansion coefficient as ceramic material. Calculation has been made to evaluate the gains of thermal barrier coatings applied on gas turbine blades. The study considers a top ceramic coating Zirconia stabilized with 8 wt.% Y2O3 on a NiCoCrAlY bond coat and Inconel 738LC as substrate. For different thickness and different cooling air flow rates, a thermodynamic analysis has been performed and pollutants emissions (CO, NOx) have been estimated to analyze the effect of rising the gas inlet temperature. The effect of thickness and thermal conductivity of top coating and the mass flow rate of cooling air have been analyzed. The model for heat transfer analysis gives the temperature reduction through the wall blade for the considered conditions and the results presented in this contribution are restricted to a two considered limits: (1) maximum allowable temperature for top layer (1200?C) and (2) for blade material (1000?C). The model can be used to analyze other materials that support higher temperatures helping in the development of new materials for thermal barrier coatings.

scholarly journals Analytical and Experimental Study of Residual Stresses in Thermal Barrier Coatings Deposited on Gas Turbine Blades in Laboratory Dimensions by APS and HVOF Methods to Calculate the Optimal Thickness

2021 ◽  
Vol 3 (1) ◽  
pp. 63-67
Author(s):  
Esmaeil Poursaeidi ◽  
◽  
Farzam Montakhabi ◽  
Javad Rahimi ◽  
◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Analytical Model ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Thermal Barrier ◽  
Inlet Temperature ◽  
Optimal Thickness ◽  
Barrier Coatings

The constant need to use gas turbines has led to the need to increase turbines' inlet temperature. When the temperature reaches a level higher than the material's tolerance, phenomena such as creep, changes in mechanical properties, oxidation, and corrosion occur at high speeds, which affects the life of the metal material. Nowadays, operation at high temperatures is made possible by proceedings such as cooling and thermal insulation by thermal barrier coatings (TBCs). The method of applying thermal barrier coatings on the turbine blade creates residual stresses. In this study, residual stresses in thermal barrier coatings applied by APS and HVOF methods are compared by Tsui–Clyne analytical model and XRD test. The analytical model results are in good agreement with the experimental results (between 2 and 8% error), and the HVOF spray method creates less residual stress than APS. In the end, an optimal thickness for the coating is calculated to minimize residual stress at the interface between the bond coat and top coat layers.

Running-in behaviour of thermal barrier coatings in the combustion chamber of a diesel engine

2019 ◽  
Vol 234 (1) ◽  
pp. 172-182 ◽  
Author(s):  
Anders Thibblin ◽  
Siamak Kianzad ◽  
Stefan Jonsson ◽  
Ulf Olofsson
Keyword(s):  
Heat Flux ◽  
Diesel Engine ◽  
Thermal Barrier Coatings ◽  
Yttria Stabilized Zirconia ◽  
Thermal Barrier ◽  
Heavy Duty ◽  
Stabilized Zirconia ◽  
Barrier Coatings ◽  
Heavy Duty Diesel

Thermal barrier coatings have the potential to improve the fuel efficiency of heavy-duty diesel engines by reducing heat losses. A method for in-situ measurement of heat flux from the combustion chamber of a heavy-duty diesel engine has been developed and was used to study the running-in behaviour of different thermal barrier coating materials and types of microstructures. The in-situ measurements show that the initial heat flux was reduced by up to 4.7% for all investigated thermal barrier coatings compared to a steel reference, except for an yttria-stabilized zirconia coating with sealed pores that had an increase of 12.0% in heat flux. Gd2Zr2O7 had the lowest initial value for heat flux. However, running-in shows the lowest values for yttria-stabilized zirconia after 2–3 h. Potential spallation problems were observed for Gd2Zr2O7 and La2Zr2O7.

scholarly journals CFD-Guided Development of Test Rigs for Studying Erosion and Large-Particle Damage of Thermal Barrier Coatings

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Maria A. Kuczmarski ◽  
Robert A. Miller ◽  
Dongming Zhu
Keyword(s):  
Thermal Barrier Coatings ◽  
Large Particle ◽  
Turbine Blades ◽  
High Heat ◽  
Heat Fluxes ◽  
Materials Testing ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Particle Damage ◽  
Computational Fluid Dynamics Cfd

Burner rigs are routinely used to qualify materials for gas turbine applications. The most useful rig tests are those that can replicate, often in an accelerated manner, the degradation that materials experience in the engine. Computational fluid dynamics (CFD) can be used to accelerate the successful development and continuous improvement of combustion burner rigs for meaningful materials testing. Rig development is typically an iterative process of making incremental modifications to improve the rig performance for testing requirements. Application of CFD allows many of these iterations to be done computationally before hardware is built or modified, reducing overall testing costs and time, and it can provide an improved understanding of how these rigs operate. This paper describes the use of CFD to develop burner test rigs for studying erosion and large-particle damage of thermal barrier coatings (TBCs) used to protect turbine blades from high heat fluxes in combustion engines. The steps used in this study—determining the questions that need to be answered regarding the test rig performance, developing and validating the model, and using it to predict rig performance—can be applied to the efficient development of other test rigs.

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