Using a DOE Approach to Optimize a LVPS Bond Coat and APS Top Coat for TBC Systems

Abstract Acquisition of a new LVPS and APS coating system at Delta Air Lines necessitated optimization of the coating parameters on both systems; especially for application of bond coat (LVPS) and top coat (APS) for a TBC coating system. To expedite the coating optimization; it was determined that a design of experiments (DOE) approach would best enable the establishment of the operating window for the two systems. Samples prepared were primarily evaluated for their performance while exposed to a cyclic oxidation cycle. Samples were also evaluated for the microstructure and composition using energy dispersive spectroscopy (EDS) analysis. Samples from the ceramic coating DOE were also evaluated for their erosion characteristics. Results indicate a low correlation between the individual bond coat parameters evaluated to the furnace cycle life. However; the top coat spray parameters were found to have a greater correlation to furnace cycle life and erosion performance.

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A Novel Duplex Re-NiW Based Diffusion Barrier on a Nickel-Base Superalloy for TBC Systems

Materials Science Forum ◽

10.4028/www.scientific.net/msf.595-598.127 ◽

2008 ◽

Vol 595-598 ◽

pp. 127-134 ◽

Cited By ~ 3

Author(s):

Sebastien Mercier ◽

Denis Boivin ◽

Marie Pierre Bacos ◽

Pierre Josso

Keyword(s):

Diffusion Barrier ◽

Bond Coat ◽

Alloying Elements ◽

Nickel Base Superalloy ◽

Coating Process ◽

Thermal Treatments ◽

Eds Analysis ◽

Nickel Base ◽

Tbc Systems ◽

Base Superalloy

A diffusion barrier between a 4th generation superalloy (MC-NG) and a β-(Ni, Pt)Al has been studied. The used coating process combines Re and NiW electrolytic deposits followed by thermal treatments. The diffusion barrier is composed of a continuous 3 &m thick ReWNi layer under a 10 &m thick β-(Ni, Pt)Al containing W rich precipitates. EDS analysis on as coated samples and on 50h-1100°C-Ar aged samples showed that the Re-NiW layer works as a diffusion barrier. The Al reservoir in the bond coat after aging is higher with the diffusion barrier than without. The concentrations of alloying elements are also lower in the bond coat with the diffusion barrier than without.

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The effect of bond coat type on the stab resistance of Al2O3–13 wt% TiO2 plasma sprayed ceramic coating on aramid fabrics

Surfaces and Interfaces ◽

10.1016/j.surfin.2020.100432 ◽

2020 ◽

Vol 18 ◽

pp. 100432 ◽

Cited By ~ 1

Author(s):

Peyman Manaee ◽

Zia Valefi ◽

Mostafa Goodarz

Keyword(s):

Bond Coat ◽

Ceramic Coating ◽

Stab Resistance ◽

Plasma Sprayed ◽

Aramid Fabrics

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Chemical Bonds Properties and Spontaneous Polarization of Orthogonal SrBi2Ta2O9 Crystals

Materials Science Forum ◽

10.4028/www.scientific.net/msf.848.688 ◽

2016 ◽

Vol 848 ◽

pp. 688-695

Author(s):

Xiao Hong Xiao ◽

Shi Chun Li

Keyword(s):

Spontaneous Polarization ◽

Cluster Structure ◽

Chemical Bonds ◽

Local Cluster ◽

Valence Electron Density ◽

Effective Valence ◽

Individual Bond ◽

Atomic Coordination ◽

Experimental Values ◽

The Individual

The bonds structure, atomic coordination situation and local cluster structure in SrBi2Ta2O9 were analyzed by means of the Atomic Environment Calculation (AEC), and then the SrBi2Ta2O9 crystal was decomposed into 20 pseudo-binary crystals with the crystal decomposition method. The chemical bonds properties, such as effective valence electron density and iconicity of the individual bond were calculated by the dielectric chemical bonds theory. And the correlation between chemical bonds properties and spontaneous polarization of the bismuth layered ferroelectrics was established. Finally, the spontaneous polarization in ferroelectric SrBi2Ta2O9 and other relevant ferroelectrics were calculated, which are in good agreement with the experimental values and other theoretical calculated values.

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A Comparison between CoNiCrAlY Bond Coat and Zirconia Plasma Sprayed Coatings on Creep Tests

Materials Science Forum ◽

10.4028/www.scientific.net/msf.591-593.30 ◽

2008 ◽

Vol 591-593 ◽

pp. 30-35

Author(s):

Danieli A.P. Reis ◽

Carlos de Moura Neto ◽

Antônio Augusto Couto ◽

Cosme Roberto Moreira Silva ◽

Francisco Piorino Neto ◽

...

Keyword(s):

Bond Coat ◽

Ceramic Coating ◽

Constant Load ◽

Creep Tests ◽

Engineering Ceramic ◽

Wide Range ◽

Plasma Sprayed Coatings ◽

Plasma Sprayed ◽

Engine Components ◽

Sprayed Coatings

Thermomechanical and electrical properties of zirconia-based ceramics have led to a wide range of advanced and engineering ceramic applications like solid electrolyte in oxygen sensors, fuel cells and furnace elements and its low thermal conductivity has allowed its use for thermal barrier coatings for aerospace engine components. A comparison between CoNiCrAlY bond coat and zirconia plasma sprayed coatings on creep tests of the Ti-6Al-4V alloy was studied. The material used was commercial Ti-6Al-4V alloy. Yttria (8 wt.%) stabilized zirconia (YSZ) with a CoNiCrAlY bond coat was atmospherically plasma sprayed on Ti-6Al-4V substrates by Sulzer Metco Type 9 MB. Constant load creep tests were conducted on a standard creep machine in air on coated samples, at stress levels of 520 MPa at 500°C to evaluate the oxidation protection on creep of the Ti-6Al-4V alloy. Results indicate that the creep resistance of the ceramic coating was greater than metallic coating.

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

Thermal Spray 1998: Proceedings from the International Thermal Spray Conference ◽

10.31399/asm.cp.itsc1998p1589 ◽

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.

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