scholarly journals A Mechanism of Anti-Oxidation Coating Design Based on Inhibition Effect of Interface Layer on Ions Diffusion within Oxide Scale

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 454
Author(s):  
Bo Yu ◽  
Ya Liu ◽  
Lianqi Wei ◽  
Xiaomeng Zhang ◽  
Yingchao Du ◽  
...  
Keyword(s):  
Oxide Scale ◽  
Energy Barrier ◽  
Tetrahedral Site ◽  
Interface Layer ◽  
Diffusion Behavior ◽  
Mullite Phase ◽  
Inhibition Effect ◽  
Coating Design ◽  
Oxidation Effect ◽  
Dynamics Method

In this paper, a mechanism of anti-oxidation coating design based on the inhibition effect of the interface layer on the diffusion of ions within oxide scale was introduced. The Fe2+ ions diffusion behavior in Fe3O4, Cr2FeO4, and FeAl2O4 were studied by molecular dynamics method of Nudged elastic bond. As the result shown, Fe2+ ions tended to diffuse through the vacancy at tetrahedral site in Cr2FeO4 and FeAl2O4, but diffuse through the octahedral vacancy in Fe3O4. When temperature ranged from 1073 to 1325 K, the energy barrier of Fe2+ ions diffusion in Cr2FeO4 was higher than that of FeAl2O4, and both of that were still obvious higher than that in Fe3O4. A new anti-oxidation coating was prepared based on the inhibition of interface layer consisted of FeAl2O4 to protect the carbon steel S235JR at 1200 °C for 2 h. The FeAl2O4 region was formed and observed at the interface between coating and Fe element diffusion area, and the mullite phase was distributed outside of the FeAl2O4 region. Comparing to the bare sample, the prepared coating exhibited an excellent anti-oxidation effect.

Study on the Growth of Crystalline Er2O3 Films on Si Substrates by RHEED Patterns

2011 ◽  
Vol 486 ◽  
pp. 163-166
Author(s):  
Yan Yan Zhu ◽  
Run Xu ◽  
Ze Bo Fang
Keyword(s):  
Film Growth ◽  
Interface Layer ◽  
High Energy ◽  
High Substrate Temperature ◽  
Initial Growth ◽  
High Energy Electron ◽  
Si Substrates ◽  
Good Crystallinity ◽  
Oxidation Effect

Er2O3 films with good crystallinity have been achieved on an oxidized Si (111) surface by molecule beam epitaxy. The initial growth of Er2O3 films epitaxially grown on Si surfaces is investigated by in situ reflection high energy electron diffraction. An interface layer was formed at the very beginning of the growth of Er2O3 film on Si, which is supposed to be attributed to the Er atom catalytic oxidation effect. The results obtained indicate that with the film growth process continued, oxygen deficient Er oxide captures oxygen from the interface layer which is formed inevitably at the initial growth of Er2O3 film and thus reduce and even remove the interface layer if the condition of O2 pressure is insufficient at a high substrate temperature such as 700°C in our case.

In situ Photoemission Study on Initial Growth of Er2O3 Films on Si(001)

2008 ◽  
Vol 373-374 ◽  
pp. 625-628 ◽  
Author(s):  
Y.Y. Zhu ◽  
Z.B. Fang ◽  
Shu Chen ◽  
C. Liao ◽  
Z.M. Jiang
Keyword(s):  
Growth Process ◽  
Film Growth ◽  
Interface Layer ◽  
High Substrate Temperature ◽  
Photoemission Spectroscopy ◽  
Initial Growth ◽  
Photoemission Study ◽  
Oxidation Effect ◽  
Synchrotron Radiation Photoemission

Synchrotron radiation photoemission spectroscopy was used to study the initial growth of Er2O3 films on Si in O2 pressures of 7×10-6 Torr. An interface layer was observed at the initial growth of Er2O3 film on Si, which is supposed to be attributed to the effect of the Er atom catalytic oxidation effect. With the film growth process continued, oxygen deficient Er oxide will capture oxygen from the interface layer which is formed inevitably at the initial growth of Er2O3 film and thus reduce and even remove the interface layer if the condition of O2 pressure is a little insufficient at a high substrate temperature.

Structural Imperfections in thin Oxide Films Formed on Some Fe- and Ni-Base Alloys

1970 ◽  
Vol 28 ◽  
pp. 510-511
Author(s):  
L. P. Lemaire ◽  
D. E. Fornwalt ◽  
F. S. Pettit ◽  
B. H. Kear
Keyword(s):  
Oxide Scale ◽  
Oxidation Process ◽  
Short Circuit ◽  
Protective Oxide ◽  
Protective Oxide Scale ◽  
Thin Oxide Films ◽  
Diffusion Paths ◽  
Oxidation Resistant ◽  
Structural Imperfections ◽  
Short Circuit Diffusion

Oxidation resistant alloys depend on the formation of a continuous layer of protective oxide scale during the oxidation process. The initial stages of oxidation of multi-component alloys can be quite complex, since numerous metal oxides can be formed. For oxidation resistance, the composition is adjusted so that selective oxidation occurs of that element whose oxide affords the most protection. Ideally, the protective oxide scale should be i) structurally perfect, so as to avoid short-circuit diffusion paths, and ii) strongly adherent to the alloy substrate, which minimizes spalling in response to thermal cycling. Small concentrations (∼ 0.1%) of certain reactive elements, such as yttrium, markedly improve the adherence of oxide scales in many alloy systems.

Morphologies of Nonadherent Al2O3 and Matching Substrate Surfaces

1972 ◽  
Vol 30 ◽  
pp. 524-525
Author(s):  
C. S. Giggins ◽  
J. K. Tien ◽  
B. H. Kear ◽  
F. S. Pettit
Keyword(s):  
Electron Microscopy ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
Substrate Surface ◽  
Morphological Features ◽  
Thermally Induced ◽  
Oxide Spallation ◽  
Oxidation Resistant ◽  
Induced Stresses ◽  
Substrate Surfaces

The performance of most oxidation resistant alloys and coatings is markedly improved if the oxide scale strongly adheres to the substrate surface. Consequently, in order to develop alloys and coatings with improved oxidation resistance, it has become necessary to determine the conditions that lead to spallation of oxides from the surfaces of alloys. In what follows, the morphological features of nonadherent Al2O3, and the substrate surfaces from which the Al2O3 has spalled, are presented and related to oxide spallation.The Al2O3, scales were developed by oxidizing Fe-25Cr-4Al (w/o) and Ni-rich Ni3 (Al,Ta) alloys in air at 1200°C. These scales spalled from their substrates upon cooling as a result of thermally induced stresses. The scales and the alloy substrate surfaces were then examined by scanning and replication electron microscopy.The Al2O3, scales from the Fe-Cr-Al contained filamentary protrusions at the oxide-gas interface, Fig. 1(a). In addition, nodules of oxide have been developed such that cavities were formed between the oxide and the substrate, Fig. 1(a).

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