Low temperature hot corrosion of CoCrAl alloys

Luthra, Krishan L.; LeBlanc, Oliver H.

doi:10.1016/0025-5416(87)90395-8

Cited by 36 publications

(20 citation statements)

References 7 publications

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“…CoCrAlY's generally out perform NiCrAlY based systems, with the high chromium containing CoCrAlY's showing best performance [8,16,[19][20][21][22] This is illustrated schematically in Figure 1 reproduced from a paper by Novak (1994) [22] and is similar to an early diagram by Mom in 1981 [21].…”

Section: Environmental Protection Coatingsmentioning

confidence: 78%

“…Since this pioneering study, much research has been undertaken into the MCrAlY series of alloys. New compositions have been identified for marine service [20,34,35], for utility turbine conditions [36,37] and for high temperature cyclic oxidation [38,39]. Thus, since 1970, the base alloy composition has changed to include NiCrAlY's, CoNiCrAlY's and NiCoCrAlY's and various oxygen active elements have been added, including Hf, Zr, Si and Ta.…”

Section: Optimisation Of Corrosion Resistant Compositionsmentioning

confidence: 99%

“…Chromised and chrome-aluminised coatings also offer protection under type II corrosion conditions. Thus silicon containing and/or chromium-rich diffusion coatings offer improved corrosion resistance at the lower temperatures that are often encountered within utility turbine environments [16,17,[19][20][21].…”

Section: Environmental Protection Coatingsmentioning

confidence: 99%

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Smart overlay coatings — concept and practice

Nicholls

Simms

Chan

et al. 2002

Surface and Coatings Technology

183

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Section: Environmental Protection Coatingsmentioning

confidence: 78%

Section: Optimisation Of Corrosion Resistant Compositionsmentioning

confidence: 99%

See 1 more Smart Citation

Smart overlay coatings — concept and practice

Nicholls

Simms

Chan

et al. 2002

Surface and Coatings Technology

183

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show abstract

“…Chromised and chrome-aluminised coatings also offer protection under type II corrosion conditions. Thus, silicon containing or chromium-rich diffusion coatings offer improved corrosion resistance at the lower temperatures that are often encountered within utility turbine environments (Nicholls et al, 1990;Luthra & LeBlanc, 1987). Overlay coatings of classic design, with 18-22% Cr and 8-12% Al, generally perform better at higher temperatures where oxidation is the dominant failure mode (above 900°C) reflecting the good adherence of the thin alumina scales, which is promoted by the presence of active elements such as yttrium.…”

Section: Effect Of Chemical Composition On the Oxidation Of Coatingsmentioning

confidence: 99%

Isothermal Oxidation Behavior of Plasma Sprayed MCrAlY Coatings

Seo¹,

Ogawa²

2012

Advanced Plasma Spray Applications

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“…Luthra [52,79] showed that Cr-rich CoCrAlY coatings have better Type II hot corrosion resistance than conventional CoCrA1Y coatings. The NiCrAIY and NiCoCrAlY are other types overlay coatings often used in gas-turbine engines and hot corrosion resistance of these coating was previously studied by the number of researchers [81,82].…”

Section: Hot Corrosion Ofpt-modified Alloys/coatings and Mcraly-basedmentioning

confidence: 99%

Optimizing the Hot-Corrosion Resistance-of-Novel gamma-Ni+gamma-prime-Ni3A1-Based Alloys and Coatings

Gleeson¹

2006

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The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT ABSTRACTHigh temperature degradation by hot corrosion (650-1000 C) and/or oxidation (>1000 C) can severely reduce the longevity of advanced gas turbine engine components. The protection of high-temperature components against hot corrosion or oxidation is typically conferred by the application of either a diffusion or overlay metallic coating that is able to form a continuous, adherent, and slow growing oxide scale. There are currently no coatings that provide adequate protection to both hot corrosion and oxidation. This study assesses and advances the performance of novel modified gamma-Ni + gamma-prime Ni3AI alloys and coatings. Significant progress was achieved in this study towards the targeted goal of establishing a metallic coating that is highly resistant to both hot corrosion and high temperature oxidation. High temperature degradation by hot corrosion (650-1000'C) and/or oxidation (>1000°C) can severely reduce the longevity of advanced gas turbine engine components. The protection of high-temperature components against hot corrosion or oxidation is typically conferred by the application of either a diffusion or overlay metallic coating that is able to form a continuous, adherent, and slow growing oxide scale. However, as is shown in this study, the resistance of state-of-the-art commercial Pt-modified P3-NiA1 diffusion aluminides and CoCrAIY-based overlay coatings against both Type I (i.e., 900 0 C) and Type II (i.e., 705TC) hot corrosion is limited. Thus, there are currently no coatings that provide adequate protection to both hot corrosion and oxidation. There is indeed a particular need for such protective coatings because many advanced aero, marine, and industrial gas-turbines operate in both hot corrosion and oxidation regimes in their duty cycle. Gleeson et al. [1] recently reported that a wide range Pt+Hf-modified y'-Ni 3 Al + yNi alloy compositions form a thin, planar, adherent, and slow growing A1 2 0 3 scale. In fact, the results reported suggest that Pt+Hf-modified y'+y coatings offer a viable superior alternative to P-NiAl(Pt)-based coatings. Thus, a main aim of the present study was to establish and assess optimum target y' +y...

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Low temperature hot corrosion of CoCrAl alloys

Cited by 36 publications

References 7 publications

Smart overlay coatings — concept and practice

Smart overlay coatings — concept and practice

Isothermal Oxidation Behavior of Plasma Sprayed MCrAlY Coatings

Optimizing the Hot-Corrosion Resistance-of-Novel gamma-Ni+gamma-prime-Ni3A1-Based Alloys and Coatings

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