Factors affecting adhesion of oxide scales on alloys

Giggins, C. S.; Kear, B. H.; Pettit, F. S.; Tien, J. K.

doi:10.1007/bf02646343

Cited by 119 publications

(34 citation statements)

References 6 publications

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“…Tien and Pettit [20] reported that elimination of interfacial cavities improved the scale-substrate adhesion in an yttrium-doped Fe-Cr-Al alloys, such that oxide spallation was not observed. Similarly, no oxide spallation was observed in an Hf-doped Ni-15.1Ta-6.7Al (wt.%) alloy, and oxide protrusions of HfO 2 were enveloped with a thin layer of Al 2 O 3 , which provided improved scale adhesion to the alloy [21]. In contrast, a Ni-15.1Ta-6.7 Al (wt.%) alloy doped with 0.04Y showed spallation of oxide scale during cooling.…”

Section: Discussionmentioning

confidence: 92%

High Temperature Oxidation of Pt–Al–Cr–Ru Alloy: Scale Morphology and Adherence

Odusote

Cornish

Papo

2012

Metallogr. Microstruct. Anal.

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Heat-treated Pt-11Al-3Cr-2Ru (at.%) alloy samples were oxidized in air for periods between 1 and 500 h in a muffle furnace at 1350°C. The morphology of the oxidized samples was examined using light microscopy and scanning electron microscopy equipped with energy dispersive spectroscopy, while an x-ray diffractometer and Raman spectroscopy were used for phase identification. The scale layers were found to be composed mainly of a-Al 2 O 3 ; they were adherent, continuous, and protective with neither a zone of discontinuous oxides nor any other internal oxidation. The alumina scale also grew from a submicron thick thin film after 1 h of oxidation to form large irregular-shaped grains after 500 h exposure, indicating increased scale thickness with oxidation time. Good adhesion of the a-Al 2 O 3 scale to the substrate of the current alloy was found to be dependent on the mechanical keying of the scale to the substrate due to protrusions of the alloy into the scale, which gave rise to an irregular scalesubstrate interface. The results suggest that the current alloy has a promising potential for high-temperature applications.

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Section: Discussionmentioning

confidence: 92%

High Temperature Oxidation of Pt–Al–Cr–Ru Alloy: Scale Morphology and Adherence

Odusote

Cornish

Papo

2012

Metallogr. Microstruct. Anal.

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“…In a thermodynamical point of view for the Fe-Cr alloying system the critical Cr-concentration required to stabilise Cr 2 O 3 is 0.04 at.% [13]. However, the experimental observations showed that the critical concentration is much higher than 0.04 at.% [14][15][16][17]. According to a kinetic point of view, Cr at the surface tries to form a continuous protective Cr 2 O 3 scale, but as it Fig.…”

Section: Effect Of Shot-peening On the Oxidation Behaviour Of Cr-12 Smentioning

confidence: 98%

Effect of Shot-peening on the Oxidation Behaviour of Boiler Steels

et al. 2011

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The presence of short diffusion paths is very important for rapid diffusion processes which are involved in forming protective oxide layers against high temperature corrosion, e.g. on boiler steels. Rapid diffusion paths can be produced by applying cold work such as shot-peening to the surface of the boiler steels prior to oxidation. The effect of shot-peening on oxidation behaviour was tested experimentally on 12 wt% Cr martensitic steel and 18 wt% Cr austenitic steel. Isothermal oxidation tests were performed at 700 and 750°C. The surface treatment proved to be very effective in improving oxidation protection at 700°C. Shot-peening the surface prior to the oxidation has an influential effect in changing the diffusion mechanisms of the elements involved in oxidation and changes the oxidation kinetics substantially at the applied conditions in this study.

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“…Hafnium has been used in nickel based superalloys as addition of 0.1÷1.0 wt.% to improve high temperature mechanical properties of equiaxed alloys [12]. Later it was discovered that Hf added in small amount to coatings on nickel and cobalt superalloys improve the adherence and durability of protective oxide scale on layers surface [13]. Moreover, it was proven that Hf addition not only reduced oxide scale growth rate but also increased oxide scale adherence [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and corrosion resistance of Hf-modified NiAl layers on nickel based superalloy Ni-Cr-Co-Mo-2Ti-1.5Al

et al. 2015

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Article discusses examination of aluminizing and Hf modification impact on the microstructure and corrosion resistance of manufactured layers with use of CVD method on a substrate of nickel based superalloyNi-Cr-Co-Mo-2Ti-1.5Al. The effect of modification process on microstructure, phase and chemical composition and corrosion resistance of manufactured layers was examined. Corrosion resistance of base material and material with protective layers was also compared. The effect of Hf modifications on surface morphology and thickness of layers and corrosion resistance of substrate was demonstrated. Keywords: superalloy, NiAl layer, intermetallic layer, oxidation, layer modification, microstructure, corrosion resistance, phase composition Streszczenie: Warstwy ochronne na bazie międzymetalicznej fazy NiAl stosowane są powszechnie do poprawy odporności na utlenianie wysokotemperaturowe odpowiedzialnych elementów turbin silników lotniczych. W pracy omówiono wyniki badań właściwości warstw NiAl oraz warstw NiAl modyfikowanych Hf oraz ich wpływu na mikrostrukturę podłoża -nadstopu niklu Ni-Cr-Co-Mo-2Ti-1,5Al. Procesy aluminiowania realizowano metodą CVD w atmosferze wodoru jako gazu nośnego. Przeprowadzono obserwacje mikrostruktury warstw oraz podłoża, badania składu chemicznego i fazowego warstw. Stwierdzono, że wytworzone warstwy wykazują ciągłość na całej powierzchni próbek, stabilność składu chemicznego i fazowego oraz nie wpływają na mikrostrukturę stopu. Słowa kluczowe: nadstop, warstwa NiAl, warstwa na bazie fazy międzymetalicznej, utlenianie, modyfikacja warstwy, mikrostruktura, odporność korozyjna, skład fazowy

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Factors affecting adhesion of oxide scales on alloys

Cited by 119 publications

References 6 publications

High Temperature Oxidation of Pt–Al–Cr–Ru Alloy: Scale Morphology and Adherence

High Temperature Oxidation of Pt–Al–Cr–Ru Alloy: Scale Morphology and Adherence

Effect of Shot-peening on the Oxidation Behaviour of Boiler Steels

Microstructure and corrosion resistance of Hf-modified NiAl layers on nickel based superalloy Ni-Cr-Co-Mo-2Ti-1.5Al

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