The influence of grain-boundary segregation of Y in Cr2O3 on the oxidation of Cr metal

Cotell, C. M.; Yurek, G. J.; Hussey, R. J.; Mitchell, D. F.; Graham, M. J.

doi:10.1007/bf00665014

Cited by 169 publications

(51 citation statements)

References 20 publications

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“…En-route to the gas interface, Y ions first segregate to the metal-scale interface and then into the scale. The Y ion follows the fastest path to the gas interface, which are the scale grain boundaries [20][21][22][23][24][25] . The presence of the Y ion at the oxide scale boundaries results in two effects.…”

Section: Discussionmentioning

confidence: 99%

Oxidation behavior of FeCr and FeCrY alloys coated with an aluminium based paint

et al. 2008

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A variety of metallic components rely on properties that are specific to the alloy and its surface. Coatings have been extensively used to protect metallic surfaces from the aggressive effects of the environment to which it is exposed. In this investigation, the high temperature oxidation behavior of a FeCr and a FeCrY alloy coated with an aluminium based paint has been studied. The objective was to form the more resistant alumina surface layer on an aluminium free alloy. Aluminium based paint coated and uncoated specimens of the two alloys were oxidized for up to 200 hours at 1000 °C in air. The oxidized specimens were examined in a scanning electron microscope coupled to an energy dispersive system and the surfaces were analyzed by X ray diffraction analysis. The aluminium based paint coating increased the oxidation resistance of the alloys, mainly over extended periods. The FeCrY alloy coated with the Al based paint exhibited the highest oxidation resistance.

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Section: Discussionmentioning

confidence: 99%

Oxidation behavior of FeCr and FeCrY alloys coated with an aluminium based paint

et al. 2008

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“…Minor alloying elements added to improve oxidation resistance, often referred to as "reactive elements" 12 , such as Y, Ce, Hf and Zr, are always found in the alumina scale. Studies have shown that they segregate strongly at alumina grain boundaries and alter the scale growth process 13,14 . Non-metallic impurities that are present in almost all commercial grade alloys may segregate to the scale/alloy interface during oxidation.…”

Section: Introductionmentioning

confidence: 99%

Impurity Effects on Alumina Scale Growth

Hou¹

2003

Journal of the American Ceramic Society

137

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Most high temperature resistant alloys oxidize to form an external alumina layer, or scale, whose slow growth protects the underlying alloy from continued aggressive oxidation. The growth of the Al 2 O 3 scale is controlled by the transport of oxygen inward and aluminum outward through it, with the rate dominated by the fastest diffusing specie down the fastest path. Components in the alloy can be incorporated into the growing Al 2 O 3 layer, hence affect the transport rates of oxygen and/or aluminum. This paper summarizes existing experimental data to assess the possible effect of these incorporated impurities on the growth rate and transport properties of Al 2 O 3 scales formed on Fe, Ni and Pt based alloys. The amount and distribution of the alloy base metal, sulfur impurity and reactive elements, such as Hf, Y, Zr and Ce, in the alumina scale are evaluated. Their effect on the oxidation and transport rates through the scale are discussed and compared with Al and O diffusion rates deduced from creep studies.

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“…[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Such insights have proven particularly useful for understanding the influence of various alloying additions on film growth, and provide a basis for improved alloy design. For example, tracer studies of Al 2 O 3 -forming alloys with and without rare earth element dopants revealed beneficial effects related to more protective, oxygen inward growth mechanisms [e.g.…”

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confidence: 99%

Tracer Film Growth Study of Hydrogen and Oxygen from the Corrosion of Magnesium in Water

Brady

Fayek

Elsentriecy

et al. 2014

J. Electrochem. Soc.

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An isotopic tracer study of the film growth mechanism for pure magnesium, AZ31B, and ZE10A (Elektron 717, E717) magnesium alloys in water at room temperature was performed. A series of individual and sequential exposures were conducted in both H 2 18 O and D 2 16 O, with isotopic tracer profiles obtained using secondary ion mass spectrometry (SIMS). The water-formed films consisted primarily of partially hydrated MgO. The SIMS sputter depth profiles indicate that H and D penetrated throughout the film and into the underlying metal, particularly for the Zr-and Nd-containing E717 alloy. Film growth for the UHP Mg involved aspects of both metal outward diffusion and oxygen/hydrogen inward diffusion. In contrast, the film on the Al-containing AZ31B alloy grew primarily by inward oxygen and inward hydrogen diffusion. The 18 O and D profiles for the film formed on E717 were the most complex, with the 18 O data most consistent with inward lattice oxygen diffusion, but the D data suggests inward, short-circuit diffusion through the film. It is speculated that preferential inward short circuit hydrogen transport may have been aided by the presence of nano Zn 2 Zr 3 particles throughout the E717 film. Such hydrogen penetration may have implications from both a corrosion resistance and hydrogen storage perspective. Magnesium alloys are of great interest because they can be used to manufacture lightweight automotive and aircraft structural materials that reduce vehicle weight and improve fuel efficiency.1-3 However, the poor corrosion resistance of Mg is a major challenge.4-6 A key contributor to the poor corrosion resistance of Mg is the inability to establish and/or maintain protective surfaces films. Surface films formed on Mg under ambient air and water conditions typically consist of mixtures of Mg(OH) 2 and MgO, with small amounts of MgCO 3 often also reported.7-12 They provide adequate protection under some circumstances, but are particularly vulnerable to disruption by salt species.The ambient corrosion of Mg differs from many corrosion-resistant structural alloy classes in that the protective surface films can become quite thick, on the order of tens to hundreds of nanometers, rather than the few nanometers typically encountered for protective films on stainless steels, for example. As such, corrosion resistance is influenced not only by classical thin film electrochemical passivity considerations, but also thermodynamic and kinetic considerations typically encountered in thick-film (> 0.5 micron range), high-temperature alloy oxidation phenomena.Isotopic tracer studies have been widely applied to studies of the high-temperature oxidation of alloys (Al, Fe, Ni, and Zr base; SiC), with significant new insights gained regarding the growth mechanism of the oxide films. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Such insights have proven particularly useful for understanding the influence of various alloying additions on film growth, and provide a basis for improved alloy design. For examp...

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The influence of grain-boundary segregation of Y in Cr2O3 on the oxidation of Cr metal

Cited by 169 publications

References 20 publications

Oxidation behavior of FeCr and FeCrY alloys coated with an aluminium based paint

Oxidation behavior of FeCr and FeCrY alloys coated with an aluminium based paint

Impurity Effects on Alumina Scale Growth

Tracer Film Growth Study of Hydrogen and Oxygen from the Corrosion of Magnesium in Water

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