Oxidation behavior of the thin layr formed on yttrium and niobium coated TiAl alloys at high temperatures.
| Project/Area Number |
07650832
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | Tohoku University |
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Principal Investigator |
INOUE Hirobumi Tohoku University, Institute for Advanced Materials Processing, Associate Professor, 素材工学研究所, 助教授 (70006039)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | High temperature oxidation / oxide layr / Titanium aluminide / Yttrium / Niobium |
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| Research Abstract |
Formation and the high temperature oxidation of the Y and Nb coating layrs have been investigated on the titanium-aluminum alloys, followed by heating under the low oxygen atmosphere at high temperatures. Angle-resolved X-ray photoelectron spectroscopy has been used for characterizing the thin oxide layrs and scales formed by oxidation at high temperatures.
The following results are summarized.
1) The effective thickness of the thin oxide layr on the uncoated TiAl alloy was estimated to be 5.0nm from the relationship between the concentration of titanium and aluminum and the take-off angle by coupling with a model, which consists of a contaminated layr and a titanium concentrated oxide layr on the matrix (the aluminum riched oxide layr). The present results suggest the predominant oxidation of titanium and the aluminum enrichment in the inner oxide layr.
2) Composition ratios of the oxidation states of titanium and aluminum were estimated in the oxide layr. It is also interesting to note that the oxide layr contains titanium and aluminum of oxidation states to be lower than Ti (II) and Al (III), respectively, obtained from the Ti2p and Al2p intensity data as a function of the take-off angle by the curve fitting method.
3) In the Y coated alloy, the predominant oxidation of aluminum occurs. The concentrations of Al (III) and Ti (II) increase and Ti (IV) decreases in the oxide layrs. The characterization is more emphasized in the Al-Y coated alloy. Nb does not affect the oxidation states of titanium and aluminum in the oxides layr of the TiAl alloy.
4) Adhesion is improved of the scale to the substrate of TiAl, Al coated and Al-Y coated alloy.
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Report
(3 results)
Research Products
(4 results)
