scholarly journals Nano-Characterization of Ceramic Top-Coat/Metallic Bond-Coat Interface for Thermal Barrier Coating Systems by Plasma Spraying

2004 ◽  
Vol 68 (6) ◽  
pp. 372-380 ◽  
Author(s):  
Satoru Takahashi ◽  
Masayuki Yoshiba ◽  
Yoshio Harada
Keyword(s):  
Thermal Barrier Coating ◽  
Plasma Spraying ◽  
Bond Coat ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Metallic Bond

scholarly journals High thickness coating of zirconium dioxide for thermal protection of metal alloys

2018 ◽  
Vol 224 ◽  
pp. 03004
Author(s):  
Irina Tsareva ◽  
Olga Berdnik ◽  
Maksim Maximov ◽  
Victor Kuzmin
Keyword(s):  
Thermal Barrier Coating ◽  
Plasma Spraying ◽  
Zirconium Dioxide ◽  
Thermal Protection ◽  
Intermetallic Layer ◽  
High Energy ◽  
Metal Alloys ◽  
Thermal Barrier ◽  
Barrier Coating

A study was made of high thickness thermal barrier coating of zirconium dioxide (up to 2 mm) formed by the method of high-energy plasma spraying on the intermetallic layer, and designed to protect the elements of the fuselage of aircraft.

Thermo-mechanical characterization of laser textured LaMgAl11O19/YSZ functionally graded thermal barrier coating

2017 ◽  
Vol 321 ◽  
pp. 146-155 ◽  
Author(s):  
Muhammed Anaz Khan ◽  
Muthukannan Duraiselvam ◽  
S.S. Panwar ◽  
Trilochan Jena ◽  
S.R. Dhineshkumar
Keyword(s):  
Thermal Barrier Coating ◽  
Mechanical Characterization ◽  
Functionally Graded ◽  
Thermal Barrier ◽  
Barrier Coating

Oxygen Transport Through the Zirconia Top Coat in Thermal Barrier Coating Systems

1998 ◽  
Author(s):  
A.C. Fox ◽  
T.W. Clyne
Keyword(s):  
Thermal Barrier Coating ◽  
Bond Coat ◽  
Ionic Conduction ◽  
Gas Permeability ◽  
Gas Permeation ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Oxygen Gas ◽  
Plasma Sprayed ◽  
Tbc Systems

Abstract The gas permeability of plasma sprayed yttria-stabilised zirconia coatings has been measured over a range of temperature, using hydrogen and oxygen gas. The permeability was found to be greater for coatings produced with longer stand-off distances, higher chamber pressures and lower torch powers. Porosity levels have been measured using densitometry and microstructural features have been examined using SEM. A model has been developed for prediction of the permeability from such microstructural features, based on percolation theory. Agreement between predicted and measured permeabilities is good. Ionic conduction through the coatings has also been briefly explored. It is concluded that transport of oxygen through the top coat in thermal barrier coating (TBC) systems, causing oxidation of the bond coat, occurs primarily by gas permeation rather than ionic conduction, at least up to temperatures of about 1000°C and probably up to higher temperatures. Top coat permeabilities appreciably below those measured will be required if the rate of bond coat oxidation is to be reduced by cutting the supply of oxygen to the interface.

On the Change in Stress State Associated with Bond Coat Oxidation during Heat Treatment of a Thermal Barrier Coating System

1997 ◽  
Author(s):  
Y.C. Tsui ◽  
T.W. Clyne ◽  
R.C. Reed
Keyword(s):  
Heat Treatment ◽  
Stress State ◽  
Oxide Layer ◽  
Thermal Barrier Coating ◽  
Bond Coat ◽  
Driving Forces ◽  
Lateral Strain ◽  
Thermal Barrier ◽  
Residual Stress State ◽  
Barrier Coating

Abstract Thermal barrier coating systems have been heat treated in order to study the oxidation kinetics of the bond coat. All the surfaces of Ni superalloy substrates were sprayed with ~100 μm of a NiCrAlY bond coat, with or without ~250 μm of a ZrO2 top coat. Thermogravimetric analysis (TGA) was used to monitor continuously the mass change as a result of oxidation of the bond coat during heating at 1000°C for 100 hours in flowing air. In addition, some specimens were heated to 1000°C in static air, cooled to room temperature, weighed and re-heated cyclically. The total exposure time was 1000 hours. Rates of weight gain were found to be higher for the cycled specimens, despite the absence of air flow. This is attributed to damage to the oxide film, which was predominantly α-Al2O3, as a consequence of differential thermal contraction stresses. The changing residual stress state during heat treatment was predicted using a previously-developed numerical model. A thin (1 mm) substrate with ~100 μm bond coat and ~250 μm ZrO2 top coat was used in these simulations, which incorporated creep of the bond coat and the lateral strain associated with oxidation. It is concluded from these computations that, while high stresses develop in the oxide layer, the associated driving forces for interfacial debonding remain relatively low, as do specimen curvature changes. It seems likely that coating spallation after extensive oxide layer formation arises because the interface is strongly embrittled as the layer thickens.

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