Thickness and composition of native oxides and near-surface regions of Ni superalloys
(2022) In Journal of Alloys and Compounds 895.- Abstract
The surface chemistry and thickness of the native oxide, hydroxide, and modified sub-surface layer of three Ni superalloys (alloy 59, 625, and 718) were determined by synchrotron X-ray Photoelectron Spectroscopy (XPS) and X-ray Reflectivity (XRR). Taking advantage of the synchrotron radiation techniques, a procedure for normalizing the photoelectron intensity was employed, which allowed for accurate quantitative analysis revealing a total oxide thickness for all samples of 12–13 Å, a hydroxide layer of 2–3 Å, and a thickness of the sub-surface alloy layer of 20–35 Å. The thickness results were compared to structural atomic models suggesting that the oxide thickness corresponds to four planes of metal cations in the oxide matrix. The XPS... (More)
The surface chemistry and thickness of the native oxide, hydroxide, and modified sub-surface layer of three Ni superalloys (alloy 59, 625, and 718) were determined by synchrotron X-ray Photoelectron Spectroscopy (XPS) and X-ray Reflectivity (XRR). Taking advantage of the synchrotron radiation techniques, a procedure for normalizing the photoelectron intensity was employed, which allowed for accurate quantitative analysis revealing a total oxide thickness for all samples of 12–13 Å, a hydroxide layer of 2–3 Å, and a thickness of the sub-surface alloy layer of 20–35 Å. The thickness results were compared to structural atomic models suggesting that the oxide thickness corresponds to four planes of metal cations in the oxide matrix. The XPS data revealed that the native oxides were enriched in Cr3+, Mo(4,5,6)+, and Nb5+, while no Ni oxide was detected. The hydroxide layer mainly contained Ni2+ and Cr3+ hydroxide. The sub-surface layer was enriched in Ni and depleted in Cr, Fe, Mo, and Nb. The obtained oxide composition can be explained using thermodynamics, and it was found that the oxide composition correlates with the enthalpy of oxide formation for the metal elements in the alloys. Finally, the advantages of synchrotron radiation for composition and thickness determination are discussed.
(Less)
- author
- organization
- publishing date
- 2022-02-25
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Corrosion, Cr, Fe, Mo, Native oxide, Nb, Ni, Nickel alloy, Oxide, Passive film, Superalloy, Synchrotron, X-ray photoelectron spectroscopy, X-ray reflectivity, XPS, XRR
- in
- Journal of Alloys and Compounds
- volume
- 895
- article number
- 162657
- publisher
- Elsevier
- external identifiers
-
- scopus:85118843201
- ISSN
- 0925-8388
- DOI
- 10.1016/j.jallcom.2021.162657
- language
- English
- LU publication?
- yes
- additional info
- Funding Information: Financial support is acknowledged from the Swedish Research Council (2018-03434 and 2020-06154) and the Swedish Foundation for Strategic Research under contract ID19-0032. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III, and we would like to thank Malte Blankenburg for assistance in using the Swedish Material Science beamline P21.2. Beamtime was allocated for proposal 20200219EC. We acknowledge FlexPES beamline scientists at MAX IV for assistance with XPS measurements. Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research council under contract 2018-07152, the Swedish Governmental Agency for Innovation Systems under contract 2018-04969, and Formas under contract 2019-02496. The authors would like to thank Dmytro Orlov and Zoran Markovski for their help with sample preparation. Funding Information: Financial support is acknowledged from the Swedish Research Counci l ( 2018-03434 and 2020-06154 ) and the Swedish Foundation for Strategic Research under contract ID19-0032 . We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III, and we would like to thank Malte Blankenburg for assistance in using the Swedish Material Science beamline P21.2. Beamtime was allocated for proposal 20200219EC. We acknowledge FlexPES beamline scientists at MAX IV for assistance with XPS measurements. Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research council under contract 2018-07152 , the Swedish Governmental Agency for Innovation Systems under contract 2018-04969 , and Formas under contract 2019-02496 . The authors would like to thank Dmytro Orlov and Zoran Markovski for their help with sample preparation. Publisher Copyright: © 2021 The Authors
- id
- db41557f-643f-4153-8072-825bb57dd6bb
- date added to LUP
- 2021-11-27 12:14:14
- date last changed
- 2023-11-23 13:14:51
@article{db41557f-643f-4153-8072-825bb57dd6bb,
abstract = {{<p>The surface chemistry and thickness of the native oxide, hydroxide, and modified sub-surface layer of three Ni superalloys (alloy 59, 625, and 718) were determined by synchrotron X-ray Photoelectron Spectroscopy (XPS) and X-ray Reflectivity (XRR). Taking advantage of the synchrotron radiation techniques, a procedure for normalizing the photoelectron intensity was employed, which allowed for accurate quantitative analysis revealing a total oxide thickness for all samples of 12–13 Å, a hydroxide layer of 2–3 Å, and a thickness of the sub-surface alloy layer of 20–35 Å. The thickness results were compared to structural atomic models suggesting that the oxide thickness corresponds to four planes of metal cations in the oxide matrix. The XPS data revealed that the native oxides were enriched in Cr<sup>3+</sup>, Mo<sup>(4,5,6)+</sup>, and Nb<sup>5+</sup>, while no Ni oxide was detected. The hydroxide layer mainly contained Ni<sup>2+</sup> and Cr<sup>3+</sup> hydroxide. The sub-surface layer was enriched in Ni and depleted in Cr, Fe, Mo, and Nb. The obtained oxide composition can be explained using thermodynamics, and it was found that the oxide composition correlates with the enthalpy of oxide formation for the metal elements in the alloys. Finally, the advantages of synchrotron radiation for composition and thickness determination are discussed.</p>}},
author = {{Larsson, Alfred and D'Acunto, Giulio and Vorobyova, Mariya and Abbondanza, Giuseppe and Lienert, Ulrich and Hegedüs, Zoltan and Preobrajenski, Alexei and Merte, Lindsay R. and Eidhagen, Josefin and Delblanc, Anna and Pan, Jinshan and Lundgren, Edvin}},
issn = {{0925-8388}},
keywords = {{Corrosion; Cr; Fe; Mo; Native oxide; Nb; Ni; Nickel alloy; Oxide; Passive film; Superalloy; Synchrotron; X-ray photoelectron spectroscopy; X-ray reflectivity; XPS; XRR}},
language = {{eng}},
month = {{02}},
publisher = {{Elsevier}},
series = {{Journal of Alloys and Compounds}},
title = {{Thickness and composition of native oxides and near-surface regions of Ni superalloys}},
url = {{http://dx.doi.org/10.1016/j.jallcom.2021.162657}},
doi = {{10.1016/j.jallcom.2021.162657}},
volume = {{895}},
year = {{2022}},
}