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Showing 1 to 20 of 23 for “"thermal barrier coating"”.
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Geometric Effects of Thermal Barrier Coating Damage on Turbine Blade Temperatures
<p>Thermal barrier coatings (TBC) found on turbine blades are a key element in the performance and reliability of modern gas turbines. During the life of the turbine components, the TBC surface may be damaged due to manufacturing imperfections, handling damage, service spalling, or service impact …
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Atomistic and finite element modeling of zirconia for thermal barrier coating applications
… Due to its high melting temperature, low thermal conductivity, and high-temperature stability, zirconia based ceramics have been widely used for thermal barrier coatings (TBCs). When TBC is exposed to thermal cycling during real applications, the TBC may fail due to several mechanisms: (1) …
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Microstructural characterization of a plasma sprayed ZrO2-Y2O3-TiO2 thermal barrier coating
The use of plasma sprayed ceramic coats as thermal barrier coatings (TBCs) for the protection of metallic structures and equipment from severe thermal, abrasive and corrosive conditions has been documented extensively in the last two decades. The state-of-the-art TBCs consist of a double layer …
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Investigation into the optimal cooling configuration for a gas turbine airfoil utilizing a thermal barrier coating
… cooling effectiveness of airfoil's utilizing a thermal barrier coating. In this study it was found that the addition of a 0.84D thick TBC to an internally cooled flat plate yields a 130% improvement in the overall cooling effectiveness. This result along with increased reliability of TBCs …
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In situ control of lubricant properties for reduction of power cylinder friction through thermal barrier coating
… discusses the implementation of insulation or thermal barrier coating (TBC) as a means of reducing local oil viscosity and power cylinder friction in internal combustion engines with minimal side effects of increased wear. TBC is selectively applied to the outside diameter of the cylinder liner …
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Thermal Evolution of MAS, YSZ and GZO Thermal Barrier Coating Materials in Benign and CMAS Rich Environments
Abradable thermal barrier coatings (TBCs) play a crucial role as thermal insulators and dynamic seals in turbine engines. However, the conventional choice, yttria-stabilised zirconia (YSZ), exhibits vulnerabilities, such as sintering induced stiffening, phase transformations, and susceptibility to …
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The effect of bond coat oxidation on the microstructure and endurance of two thermal barrier coating systems
A series of isothermal and cyclic oxidation tests were carried out on two thermal barrier coating systems consisting of a CMSX-4 nickel-based superalloy substrate, NiCoCrAlY overlay bond coat applied by two different techniques and a yttria stabilised zirconia topcoat applied by electron beam …
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Air Plasma Sprayed Thermal Barrier Coatings: Experiments and Finite Element Analysis
… failure mechanism of an air plasma sprayed thermal barrier coating commonly used in combustor applications, and to use that failure mechanism as a basis in developing a life prediction strategy. The research consisted of an experimental phase, in which the failure mechanism was identified …
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Impact of aerothermal modeling on the estimation of turbine blade life
The impact of aerothermal modeling on estimates of turbine blade heat transfer and life was assessed for three high pressure turbine blades. The work was conducted as part of a project aimed at the evaluation of the effect of variability on turbine life. Pressure and thermal loads were extracted …
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Experimental and Computational Investigation of Thermal-Flow Characteristics of Gas Turbine Reverse-Flow Combustor
… With the modern advancement in metallurgy and thermal-barrier coating technologies, it may become possible to remove this sheath to recover the pressure losses without melting the combustor chamber. However, without the sheath, the flow inside the dump diffuser may exert nonuniform cooling on …
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Modeling Behaviour of Damaged Turbine Blades for Engine Health Diagnostics and Prognostics
… damage to the structural material and thermal barrier coating as well as the onset of damage causing structural failure.
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Finite element analysis of combined fracture and delamination on coated substrate under normal and tangential loading
Coating systems provide substrate protection from mechanical and thermal failure. Coating is subjected to contact loading of normal and tangential loading, originated from contact pressure and sliding contact. In this thesis, aeroengine brittle material has been modelled to simulate coating failure …
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Nondestructive Analysis of Advanced Aerospace Materials via Spectroscopy and Synchrotron Radiation
… response and failure mechanisms. In this study, thermal barrier coating samples applicable to turbine blades of jet engines were studied using Raman and Photoluminescence spectroscopy as well as Synchrotron X-ray diffraction while Kevlar based fiber composites applicable to ballistic resistant …
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Modelling Thermal Conductivity of Porous Thermal Barrier Coatings for High-Temperature Aero Engines
Thermal Barrier Coatings (TBC) are used to shield hot sections of gas turbine engines, helping to prevent the melting of metallic surfaces. TBC is a sophisticated layered system that can be divided into top coat, bond coat, and the super-alloy substrate. The highly heterogeneous microstructure of …
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Laser surface modification of steel
… micro- Vickers diamond indentation. A customized thermal fatigue system was used to investigate the effect of surface roughness on the modified surface fatigue properties. A modified surface grain with an ultrafine size of less than 500 nm was observed to be achievable. A modified surface depth …
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Synchrotron X-Ray Diffraction and Piezospectroscopy used for the Investigation of Individual Mechanical Effects from Environmental Contaminants and Oxide Layer Undulations in Thermal Barrier Coatings
<p>The durability of Thermal Barrier Coatings (TBCs) used on the turbine blades of aircraft and power generation engines has been known to be affected by sand particle ingression comprised of Calcium-Magnesium-Alumina-Silicate (CMAS). Previous studies have shown that these effects present …
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On the oxidation of high-temperature alloys, and its role in failure of thermal barrier coatings
Thermal barrier coating (TBC) systems are applied to superalloy turbine blades to provide thermal insulation and oxidation protection. A TBC system consists of (a) an outer oxide layer that imparts thermal insulation, and (b) a metallic layer that affords oxidation protection for the substrate …
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Bonding mechanisms in the application of thermal barrier coatings to turbine blades.
Thermal barrier coatings (TBC's) are used to protect gas turbine blades from environmental degradation as well as to increase thermodynamic efficiency. Most TBC systems consist of a ceramic thermal barrier coating such as partially stabilized zirconia adhering to an oxidation resistant bond coat, …
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Hot corrosion behaviour of new candidates for thermal barrier coatings application in turbine simulated environments
Thermal barrier coatings (TBCs) are used gas turbine engines. The current material of choice (YSZ) degrades when it contacts with impurities arise from low quality fuels such vanadium and sulfur. YSZ cannot be used in temperature higher than 900˚C. Higher efficiency and performance of gas turbine …
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