Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 38 for “"Thermal barrier coatings"”.
-
Bondcoat developments for thermal barrier coatings
… has lead to the widespread use of surface coatings technology to protect hot-section componentry from the harsh operating environment. The ongoing drive towards higher operating temperatures has lead to an interest, over the last few years, in thermal barrier coatings (TBCs). TBCs are …
-
The Constitutive Behavior of Thick Thermal Barrier Coatings
Plasma-sprayed thick thermal barrier coatings on the order of a millimeter are currently being developed for use in diesel engines with operating temperatures of about 800°C. In this environment, coatings will be subjected to thermomechanical compressive strain cycles that correspond to the …
-
The Deformation and Fracture of Thick Thermal Barrier Coatings
Plasma-sprayed thick thermal barrier coatings (TTBCs) are being developed for thermal protection of diesel engine components in high temperature service. Comparing to thin thermal barrier coatings used in gas turbine industry, increased thickness causes some TTBCs failure to occur within the bulk …
-
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 …
-
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, …
-
In-situ synchrotron studies of turbine blade thermal barrier coatings under extreme environments
Thermal Barrier Coatings have been used for decades to impose a thermal gradient between the hot combustion gases and the underlying superalloy substrate in engine turbine blades. Yttria Stabilized Zirconia (YSZ) is an industry standard high temperature ceramic for turbine applications. The …
-
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 …
-
Stress and Damage Analyses of Thermal Barrier Coatings Under Cyclic Thermal Loading Conditions
The premature failure of the thermal barrier coatings (TBCs) system is a preliminary phenomenon that can significantly limit their applications in gas turbine engines. The delamination of TBCs occurs typically at interfaces between the top coat and bond coat due to thermal mismatch stress via both …
-
Nondestructive Evaluation Of Thermal Barrier Coatings With Thermal Wave Imaging And Photostimulated Luminescence Spectroscopy
… beyond material limits is by applying thermal barrier coatings (TBCs) to hot section components. TBCs provide a thermal gradient between the hot gases and metallic substrate, and allow an increase in turbine inlet temperatures of 100-150ºC. However, spallation of TBCs can cause …
-
Theoretical study on toughening and design against fracture of functionally graded thermal barrier coatings
Functionally graded thermal barrier coatings (FG TBCs) are advanced multi-phase composites that are engineered to have a smooth spatial gradation of material constituents, which are normally ceramics and metal. The smooth gradation results in the reduction of thermal stresses, minimization or …
-
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 …
-
Thermomechanical properties of novel lanthanum zirconate based thermal barrier coatings - an integrated experimental and modeling study
<p>Thermal barrier coatings (TBCs) are refractory materials deposited on gas turbine components, which provide thermal protection for metallic components at operating conditions. The current state-of-art TBC material is yttria-stabilized zirconia (YSZ), whose service temperature is limited to 1200 …
-
Deposition of yttria-stabilized zirconia thermal barrier coatings by laser-assisted plasma coating at atmospheric pressure
… to deposit the yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBC) at atmosphere pressure. These coatings can be applied on silicon wafers, and multi-layer nickel-based superalloy substrates (René N5), by a new deposition technique called laser-assisted plasma coating at atmospheric …
-
The effect of sintering and CMAS on the stability of plasma-sprayed zirconia thermal barrier coatings
State of the art thermal barrier coatings (TBCs) for gas turbine applications comprise (7 wt.%) yttria partially stabilized zirconia (7YSZ). 7YSZ offers a range of attractive functional properties – low thermal conductivity, high thermal expansion coefficient and high in-plane strain tolerance. …
-
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 …
-
Cure Kinetics of Two Part Epoxy Resin and the Effect on Characterization of Thermal Barrier Coatings
… gas turbine engines by increasing power and thermal efficiencies while simultaneously reducing cost. Turbine engines operate under high temperatures and therefore thermal barrier coatings (TBCs) composed of yttria-stabilized zirconia (YSZ) play an important role in improving the performance …
-
Effects Of Bond Coat Surface Preparation On Thermal Cycling Lifetime And Failure Characteristics Of Thermal Barrier Coatings
Thermal barrier coatings (TBCs) have been widely used in gas turbine engines to protect the underlying metal from high operating temperature so as to improve the durability of the components and enhance the engine efficiency. However, since the TBCs always operate in a demanding high-temperature …
-
Experiments and modeling of multilayered coatings and membranes : application to thermal barrier coatings and reverse osmosis membranes
… for characterizing interfacial delamination of thermal barrier coatings. The proposed methodology involves novel experiments-plus numerical simulations in order to determine the material parameters describing such failure when the interface is modeled using traction-separation constitutive laws. …
-
Non-destructive Microstructural Evaluation Of Yttria Stabilized Zirconia, Nickel Aluminides And Thermal Barrier Coatings Using Electrochemical Impedance Spectroscopy
… should be increased in the gas turbine engines, thermal barrier coatings (TBCs) have gained significant applications in increasing the gas inlet temperatures. Insulating characteristics of ceramic TBCs allow the operation at up to 150~250 ˚C higher gas temperatures. Because of the severe turbine …
-
In-Situ Investigations of Calcium-Magnesium-Aluminosilicates (CMAS) Infiltration Effects on Thermal Barrier Coatings Under Extreme Environments Replicating Jet Engines
… interact and degrade the high temperature thermal barrier coatings (TBC) protecting underlying superalloy turbine blades vital to engine operation. These CMAS particulates melt within the engine and infiltrate into the ceramic coatings. In electron-beam physical vapor deposited (EB-PVD) …
Page 1 of 2