Hot corrosion and oxidation behavior of a novel Pt+Hf-modified γ′-Ni3Al+γ-Ni-based coating

Deodeshmukh, Vinay; Mu, N.; Li, B.; Gleeson, Brian

doi:10.1016/j.surfcoat.2006.07.250

Cited by 69 publications

(34 citation statements)

References 19 publications

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“…The second stage could be a pack or CVD process to increase the Al, Cr, Hf, etc. content of the coating after Pt-plating [5,7,15,16]. The first γ+γ' coatings [3,4,9,15] made at ORNL/TTUused ~7µm Pt, the same amount as in conventional low activity chemical vapor deposition aluminide coatings [17], and a 2h vacuum anneal at 1150° or 1175°C.…”

Section: Coating Fabricationmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9] However, limited information is available about their fabrication, performance and limitations. The current study is being conducted to evaluate the potential of this class of coatings for next generation power generation applications where long-term durability and improved corrosion resistance are issues.…”

Section: Introductionmentioning

confidence: 99%

“…Coatings based on γ+γ' compositions may be attractive for this application because they are reported to have lower Al interdiffusion [2], which may result in increased lifetime, and good hot corrosion resistance. [5] Like aero-turbines, the current generation of land-based turbines relies on TBC's to protect hot section components. Lifetime of TBCs has been related to the adhesion of the alumina scale that forms at the interface between the metallic bond coating and the low thermal conductivity, ceramic (typically Y 2 O 3 -s t a b i l i z e d ZrO 2 (YSZ)) top coat.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Performance of Pt-Modified Alumina-Forming Coatings and Model Alloys

Pint¹,

Haynes²,

More³

et al. 2008

Superalloys 2008 (Eleventh International Symposium)

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The oxidation behavior of two-phase, γ+γ' Pt diffusion coatings and model alloys has been evaluated to better understand the potential of this class of coatings for power generation applications. Coatings were deposited on both directionallysolidified alloy 142 and single crystal N5 superalloys. Fabrication issues such as initial Pt thickness and annealing temperature were evaluated. Oxidation testing was performed in both dry O 2 and with the addition of H 2 O to study the performance of γ+γ' and conventional coating materials. After exposure for 1000, 1-h cycles at 1150°C in dry O 2 , a γ+γ' coating on N5 had evolved into a thicker, almost continuous γ' layer with the Pt content dropping to ~7at.% in this layer and diffusing ~250 µm into the substrate, disrupting the γ+γ' substrate microstructure. Characterization of the oxide formed on a γ+γ' composition showed that even 30 at.%Pt did not prevent the formation of a Ni-rich spinel layer at 1200°C. In order to assist the coating development process, model alloys also were evaluated. Other Pt group metals (Pd and Ir) were evaluated as well as the addition of Cr and various Hf levels. As expected, Cr and Hf were beneficial for oxidation resistance. However, Pd was not an adequate replacement for Pt because of the multi-phase microstructure that formed. A γ+γ' composition had a 1000°C yield stress in compression that was significantly higher than γ'-Ni 3 Al or β-NiAl. Also, the thermal expansion coefficient was very similar to other Ni-Al alumina-formers. The performance of γ+γ' compositions are very promising, however, sensitivity to superalloy substrate composition, Pt interdiffusion during long-term service, spinel formation and the potential need for a secondary processing step are areas of concern for this class of coatings.

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Section: Coating Fabricationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Performance of Pt-Modified Alumina-Forming Coatings and Model Alloys

Pint¹,

Haynes²,

More³

et al. 2008

Superalloys 2008 (Eleventh International Symposium)

View full text Add to dashboard Cite

show abstract

“…Although metal coatings can guarantee the long-term performance of TiAl alloys at high temperatures [8][9][10], element diffusion often appears at the interface between the coating and substrate, which, consequently, results in coating degradation [11][12][13]. Al 2 O 3 ceramic coatings can effectively protect TiAl alloys against oxidation at high temperatures and no diffusion occurs at the interface during service [14,15], which is beneficial to both the properties of the substrate alloys and Al 2 O 3 coatings [13].…”

Section: Introductionmentioning

confidence: 99%

Influence of Solvent and Electrical Voltage on Cathode Plasma Electrolytic Deposition of Al2O3 Antioxidation Coatings on Ti-45Al-8.5Nb Alloys

Yang

Jiang

Ding

et al. 2018

Metals

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Al 2 O 3 coatings were prepared on Ti-45Al-8.5Nb alloys via cathodic plasma electrolysis deposition (CPED) in both 1.2 M Al(NO 3 ) 3 aqueous and ethanolic solutions. Different voltages were also applied during the deposition process to optimize coating properties. Coatings deposited in both solutions mainly consisted of γ-Al 2 O 3 , with some Al(OH) 3 found in coatings prepared in aqueous solution. Coatings prepared in ethanol solution exhibited better oxidation resistance at 900 • C as well as better substrate adhesion, which was mainly due to smaller crater sizes on coating surfaces. The deposition process was discussed in detail and the reason for the smaller craters examined. The results suggested that solution surface tension mainly influenced the average diameter of hydrogen bubbles that formed on cathode surfaces during the process. Smaller bubbles lead to both lower current densities on cathodes and smaller crater sizes on coatings.

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“…e most effective method is the addition of elements or compounds such as Hf, Y, Zr, Cr, Pd, Pt, and SiC [25][26][27][28][29][30][31], which can change the localized concentration of aluminum and reduce its growth rate. Gleeson et al [32] indicate that the addition of Pt has beneficial effects in promoting the formation of a stable Al 2 O 3 scale.…”

Section: Introductionmentioning

confidence: 99%

Effect of the Noble Metals Addition on the Oxidation Behavior of Ni₃Al

Ramos-Hernández

Porcayo-Calderón

Mayén³

et al. 2018

Advances in Materials Science and Engineering

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is paper discusses the effect of the addition of noble metals on the microstructure, mechanism, and oxidation kinetics of the Ni 3 Al intermetallic alloy. Ni 3 Al was doped with 1% (atomic percent) of Au, Ag, Pd, and Pt. Oxidation behavior of the alloys was evaluated at 900, 1000, and 1100°C in O 2 for 24 hours. XRD analysis showed that the addition of noble metals favored the oxide growth on preferential crystallographic planes. In addition, the preferential substitution of the noble metals in the Ni 3 Al structure modifies the surface composition by increasing the Al/Ni ratio. It was observed that most of the alloys showed a subparabolic behavior, and only the intermetallic base and the alloy doped with Ag show a parabolic behavior at 900°C. e developed oxides were analyzed both superficially and in cross section by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA). It was evident that only the intermetallic base showed the formation of a duplex oxide scale (Al 2 O 3 /NiO). e alloys doped with noble metals showed the oxide growth practically of pure Al 2 O 3 . is was due to a decrease in the diffusion of the Ni cations because of the presence of the noble metals in the crystalline structure.

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Hot corrosion and oxidation behavior of a novel Pt+Hf-modified γ′-Ni3Al+γ-Ni-based coating

Cited by 69 publications

References 19 publications

The Performance of Pt-Modified Alumina-Forming Coatings and Model Alloys

The Performance of Pt-Modified Alumina-Forming Coatings and Model Alloys

Influence of Solvent and Electrical Voltage on Cathode Plasma Electrolytic Deposition of Al2O3 Antioxidation Coatings on Ti-45Al-8.5Nb Alloys

Effect of the Noble Metals Addition on the Oxidation Behavior of Ni₃Al

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Hot corrosion and oxidation behavior of a novel Pt+Hf-modified γ′-Ni3Al+γ-Ni-based coating

Cited by 69 publications

References 19 publications

The Performance of Pt-Modified Alumina-Forming Coatings and Model Alloys

The Performance of Pt-Modified Alumina-Forming Coatings and Model Alloys

Influence of Solvent and Electrical Voltage on Cathode Plasma Electrolytic Deposition of Al2O3 Antioxidation Coatings on Ti-45Al-8.5Nb Alloys

Effect of the Noble Metals Addition on the Oxidation Behavior of Ni3Al

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Effect of the Noble Metals Addition on the Oxidation Behavior of Ni₃Al