On the growth of al2o3 scales

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August undefined, 2024

WebThis study was undertaken to investigate and compare the effects of a yttrium addition on the oxide scale development of α-Cr2O3- and α-Al2O3-forming alloys under isothermal oxidation conditions. The alloys had a nominal composition (in wt.%) of Ni–30Cr, Ni–30Cr–0.5Y, Ni–30Cr–5Al, and Ni–30Cr– 5–Al–0.5Y. They were oxidized in air for 50 … Web15 de ago. de 2005 · Thermally grown, alpha-Al2O3 external scales formed on alloys after oxidation in pure oxygen at temperatures between 1000° and 1500°C were analyzed …

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WebA layered oxide scale was established on a model γ-Ni–28Cr–11Al (at.%) alloy after isothermal oxidation for several minutes at 1100°C. The layered scale consisted of an NiO layer at the oxide/gas interface, an inner Cr2O3 layer, and an α-Al2O3 layer at the oxide/alloy interface. WebThe formation and growth of Al2O3 scales on (beta)-NiAl were studied using electron microscopy and other analytical techniques to gain an understanding of the oxidation properties of (beta)-NiAl and of alumina-forming alloys, in general. The transient and mature stages of oxidation were studied as well as the transformation stage during which the … chip catcher

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WebIn order to determine the growth mechanism of α alumina scales, cationic and anionic diffusion studies have been performed on scales developed on three alumina former Fe-Cr-Al alloys. Two of them were classically elaborated and differed by the presence or not of implanted yttrium. The third one is an ODS alloy, the MA 956. First, the oxidation … WebThe addition of Pt improves α-Al 2 O 3 scale adhesion in cyclic testing at 1150°C and 1200°C. However, in comparison with aluminides which contain reactive elements (e.g. Zr and Hf), the beneficial effect of Pt was not as great. SEM and TEM analysis of the oxides indicated little effect of the Pt on scale microstructure. Using TEM/EDS ... grant hill age

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On the growth of Al2O3 scales - ScienceDirect

WebMicrostructural observations were used as the basis for a discussion of the formation and growth of voids in alumina scales. Reactive-element additions to alloys and alloy desulfurization appear to inhibit the growth of interfacial voids, thus improving scale adhesion. This phenomenon is analyzed in terms of surface energies. In addition, a … Web1 de jun. de 1999 · The morphology and growth kinetics of protectiveα-Al2O3 scales formed duringhigh-temperature oxidation of the Fe-Cr-Al andFe-Cr-Al-Y alloys were … grant hill all the smokeWebThe formation and growth of Al2O3 scales on (beta)-NiAl were studied using electron microscopy and other analytical techniques to gain an understanding of the oxidation … grant hill and his parents

"Web12 de jan. de 2024 · It is widely accepted that the growth of protective α-Al2O3 scales on Ni-based alloys is governed by the inward diffusion of oxygen through the oxide grain boundaries (GB). However, there is also some outward diffusion of metal ions to the surface, but it is difficult to quantify. In this work we apply atomic force microscopy, scanning … " - On the growth of al2o3 scales

On the growth of al2o3 scales

Growth of crystalline Al2O3 via thermal atomic layer deposition ...

WebThe microstructural development of Al2O3 scales on NiCrAl alloys has been examined by transmission electron microscopy. Voids have been observed within grains in scales formed on a pure NiCrAl alloy. Both voids and oxide grains grew measurably with oxidation time at 1100 C. The size and amount of porosity decreased towards the oxide-metal growth … Web16 de dez. de 2024 · An external ultrathin α-Al2O3 scale grown on the Ni-base alloy 602 CA during air oxidation at 800 °C was characterized by means of high-resolution TEM/EDX and electron diffraction. Alloy samples pre-oxidized at 800 °C were subsequently exposed at 1100, 1150 and 1200 °C for up to 100 h. Whereas the external alumina remained stable …

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WebInterim Professor / W3 Vertretungsprofessor in Heterogeneous Catalysis at Leipzig University. Senior Scientist and Group Leader in X-ray Microscopy at Karlsruhe Institute of Technology. Guest Scientist at DESY. Research interests include applying synchrotron radiation to understand fundamental processes of catalyst synthesis, operating … Web11 de abr. de 2024 · The addition of Pd to Pt-based diesel oxidation catalysts is known to enhance performance and restrict the anomalous growth of Pt nanoparticles when subjected to aging at high temperatures in oxidative environments. To gain a mechanistic understanding, we studied the transport of the mobile Pt and Pd species to the vapor …

WebDoi DOI: 10.1016/j.actamat.2013.07.024 Abstract WebAl2O3 scale development on iron aluminides - Volume 21 Issue 6. ... The structure and phase of the Al 2 O 3 scale that forms on an Fe 3 Al-based alloy Fe-28Al-5Cr ... Clarke, D.R.: Lateral growth kinetics of α-alumina accompanying the formation of a protective scale on (111) NiAl during oxidation at 1100 °C. Appl.

WebThe internal microstructure and growth kinetics of Al2O3 scales on Ni-15Cr-13Al (wt percent) are investigated by TEM and analyzed in relation to models of diffusivity. … Web29 de out. de 2024 · The effect of Cr on the microstructure and growth of Al2O3 scale that forms on Fe–4Cr–6Al and Fe–24Cr–6Al alloys during long-term oxidation at 1000 °C was …

Web1 de out. de 2013 · On the growth of Al2O3 scales. October 2013; Acta Materialia 61(18):6670-6683; ... Further, (a) and (c) show the case for scale growth at the scale …

WebThe development, growth, and adhesion of α-Al 2 O 3 scales on platinum-aluminum alloys containing between 0.5 and 6 wt.% aluminum have been studied at temperatures in … grant hill and tamia childrenWeb12 de abr. de 2024 · In this approach, a thin ZnO template/film was initially grown on the substrate by PLD at ~300 °C under ~10 milliTorr (1.3 Pa) O2 background pressure, followed by growth of either ZnO or Al2O3-ZnO, using PLD and RFMS simultaneously under 0.1–0.5 Torr (13–67 Pa), and Ar or Ar/O2 background in the substrate temperate range of … chip cat feederWebUnderstanding the growth of Al 2 O 3 scales requires knowledge of the details of the chemical reactions at the scale–gas and scale–metal interfaces, … grant hill and tamia weddingWeb12 de mar. de 2014 · We report the growth of crystalline Al2O3 thin films deposited by thermal Atomic Layer Deposition (ALD) at 200 °C, which up to now has always resulted in the amorphous phase. ... due to the nanometer size scale of the film/substrate combination. grant hill artWeb31 de jan. de 2024 · Request PDF On Jan 31, 2024, E. C. Dickey and others published The Effect of Platinum on the Growth and Adhesion of α-Al2O3 Scales Find, read and … grant hill and shaqWeb12 de out. de 2024 · High temperature oxidation of alumina-forming MAX phases, Ti2AlC and Cr2AlC, were examined under turbine engine environments and coating … grant high school portland mascotWeb10 de abr. de 2024 · Polysilicon (poly-Si) passivating contacts have enabled some of the highest lab-scale crystalline silicon ... O/Al ratio, density, and hydrogen content of as-deposited and annealed Al 2 O 3 layers deposited using varying ALD growth conditions. The temporal ALD Al 2 O 3 layers were annealed at 450 °C (20 min in N 2), ... grant hill ankle injury