High heat flux exposures of coated GRCop-84 substrates

Raj, S. V.; Ghosn, Louis J.; Robinson, C. S.; Humphrey, Donald L.

doi:10.1016/j.msea.2006.12.133

Cited by 27 publications

(14 citation statements)

References 6 publications

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“…N1CrAlY and NiAI have been proposed as protective top coats for GRCop-84 rocket engine combustion liners for reusable launch vehicles using Cu-Cr or Cu-Cr-AI bond coats (Ref. 14). Figure 7 compares the thermal expansions for Cu-8%Cr, Cu-26%Cr, Cu-8%Cr-1%Al, N1AI, NiCrAIY and GRCop-84 (Ref.…”

Section: Nialmentioning

confidence: 99%

“…rocket engine reveal that for a top coat thickness of about 0.1 mm, the interface temperatures are likely to be less than 625 K (Ref. 14). Indeed, finite element analyses of the out-of-plane stresses developed during these thermal cycles reveal that their magnitudes are identical under these high heat flux conditions for both Cu-8%Cr and Cu-8%Cr-1%A1 bond coats deposited on GRCop-84 substrates using NiCrAIY top coats (Ref.…”

Section: Cu-8 % Crmentioning

confidence: 99%

“…Indeed, finite element analyses of the out-of-plane stresses developed during these thermal cycles reveal that their magnitudes are identical under these high heat flux conditions for both Cu-8%Cr and Cu-8%Cr-1%A1 bond coats deposited on GRCop-84 substrates using NiCrAIY top coats (Ref. 14). In this case, the out-of-plane stress at the N1CrAlY/bond coat interface increased from -580 to -150 MPa in traversing from the top to the bond coat.…”

Section: Cu-8 % Crmentioning

confidence: 99%

“…28) or blistered under high heat flux conditions (Ref. 14). Unlike the more ductile NiCrAIY, the brittleness of a NiAI top coat may result in its spallation due to its inability to accommodate any thermal strain mismatch with the Cu-8%Cr-1%Al bond coat.…”

Section: Cu-8 % Crmentioning

confidence: 99%

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Thermal expansion of vacuum plasma sprayed coatings

Raj

Palczer

2010

Materials Science and Engineering: A

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Section: Nialmentioning

confidence: 99%

Section: Cu-8 % Crmentioning

confidence: 99%

Section: Cu-8 % Crmentioning

confidence: 99%

Section: Cu-8 % Crmentioning

confidence: 99%

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Thermal expansion of vacuum plasma sprayed coatings

Raj

Palczer

2010

Materials Science and Engineering: A

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“…The coatings showed a lifetime of 10 h at a Cr content of 21%. A NiCrAlY top-coat was investigated by Raj et al [5] using a Cu/Cr bond-coat on a Cu-8%Cr-4%Nb substrate. The coatings were thermally cycled in a H 2 /O 2 -flame.…”

Section: Introductionmentioning

confidence: 99%

Design of a Nickel-Based Bond-Coat Alloy for Thermal Barrier Coatings on Copper Substrates

Fiedler

Федорова

Rösler

et al. 2014

Metals

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To increase the lifetime of rocket combustion chambers, thermal barrier coatings (TBC) may be applied on the copper chamber wall. Since standard TBC systems used in gas turbines are not suitable for rocket-engine application and fail at the interface between the substrate and bond coat, a new bond-coat material has to be designed. This bond-coat material has to be chemically compatible to the copper substrate to improve the adhesion and needs a coefficient of thermal expansion close to that of copper to reduce thermal stresses. One approach to achieve this is to modify the standard NiCrAlY alloy used in gas turbines by adding copper. In this work, the influence of copper on the microstructure of NiCrAlY-alloys is investigated with thermodynamical calculations, optical microscopy, SEM, EDX and calorimetry. Adding copper leads to the formation of a significant amount of β-NiAl and α-Cr. Reducing the aluminum and chromium content leads furthermore to a two-phase fcc microstructure.

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Comparison of the Isothermal Oxidation Behavior of As-Cast Cu–17%Cr and Cu–17%Cr–5%Al Part I: Oxidation Kinetics

Raj

2008

Oxid Met

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The isothermal oxidation kinetics of as-cast Cu-17%Cr and Cu-17% Cr-5%Al in air were studied between 773 and 1,173 K under atmospheric pressure. These observations reveal that Cu-17%Cr-5%Al oxidizes at significantly slower rates than Cu-17%Cr. The rate constants for the alloys were determined from generalized analyses of the data without an a priori assumption of the nature of the oxidation kinetics. Detailed analyses of the isothermal thermogravimetric weight change data revealed that Cu-17%Cr exhibited parabolic oxidation kinetics with an activation energy of 165.9 ± 9.5 kJ/mol. In contrast, the oxidation kinetics for the Cu-17% Cr-5%Al alloy exhibited a parabolic oxidation kinetics during the initial stages followed by a quartic relationship in the later stages of oxidation. Alternatively, the oxidation behavior of Cu-17%Cr-5%Al could be better represented by a logarithmic relationship. The parabolic rate constants and activation energy data for the two alloys are compared with literature data to gain insights on the nature of the oxidation mechanisms dominant in these alloys.

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High heat flux exposures of coated GRCop-84 substrates

Cited by 27 publications

References 6 publications

Thermal expansion of vacuum plasma sprayed coatings

Thermal expansion of vacuum plasma sprayed coatings

Design of a Nickel-Based Bond-Coat Alloy for Thermal Barrier Coatings on Copper Substrates

Comparison of the Isothermal Oxidation Behavior of As-Cast Cu–17%Cr and Cu–17%Cr–5%Al Part I: Oxidation Kinetics

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