Effect of a yttrium coating on the oxidation behavior of Ni3Al (II)
SCIE
SCOPUS
- Title
- Effect of a yttrium coating on the oxidation behavior of Ni3Al (II)
- Authors
- Jung, HG; Kim, KY
- Date Issued
- 1998-06
- Publisher
- PLENUM PUBL CORP
- Abstract
- A Y-coated Ni3Al with a postheat treatment shows much better oxidation resistance than a Y-coated Ni3Al without a postheat treatment. In order to explain the effect of postheat treatment at low oxygen pressure, postheat treatment after Y-ion plating was performed in flowing hydrogen as a function of time. During these treatments, the Y-coated layer was modified into a (Y, Al)O-type oxide by reaction between Y2O3 and Al2O3. The thickness of the modified Y-layer was related to oxygen pressure and time. The Y-modified layer formed by postheat treatment acts as a barrier to the transport of oxygen. The fine ( Y, Al)O-type oxide can easily relieve growth stress by permitting easy plastic deformation, and the ( Y, Al) O-type oxide layer can absorb the thermal stress developed in the Al2O3 layer. The tensile stress generated by the difference in thermal-expansion coefficients of the ( Y, Al) O-type oxide and the Al2O3 layer compensates the large compressive stress generated by the difference in thermal-expansion coefficients of the Al2O3 layer and the Ni3Al alloy.
- Keywords
- postheat treatment; (Y, Al)O-type oxide; growth stress; thermal stress; HIGH-TEMPERATURE OXIDATION; AL-Y ALLOYS; FE-CR-AL; ALUMINUM-GARNET; REACTIVE ELEMENT; ADDITIONS; ALPHA-AL2O3; MECHANISM; SCALES; AL2O3
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/20693
- DOI
- 10.1023/A:1018807214002
- ISSN
- 0030-770X
- Article Type
- Article
- Citation
- OXIDATION OF METALS, vol. 49, no. 5-6, page. 403 - 430, 1998-06
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