Title:
METHOD OF TREATING SURFACE OF Ti-Al ALLOY AND TI-AL ALLOY OBTAINED BY THE SAME
Document Type and Number:
WIPO Patent Application WO/2009/054536
Kind Code:
A1
Abstract:
A surface treatment method for improving the unsusceptibility of a Ti-Al alloy to oxidation at high temperatures in a manner suitable for mass production; and a Ti-Al alloy. A Ti-Al alloy base containing 15-55 at.% aluminum is held with heating in a gas atmosphere containing a fluorine source gas to form a fluorine-rich layer having a thickness of 0.1-10 µm on the surface of the base. The fluorine-rich layer is regulated so as to have a maximum fluorine concentration of 2-35 at.%. When exposed to a high-temperature oxidizing atmosphere, this surface of the Ti-Al alloy base is coated with an Al2O3 coating film having extremely low oxygen permeability. This alloy hence has excellent unsusceptibility to high-temperature oxidation. Thus, the poor unsusceptibility to high-temperature oxidation which is a most serious defect of the Ti-Al alloy, which is lightweight and has a high high-temperature strength, can be improved in a manner suitable for mass production. The Ti-Al alloy thus treated can be advantageously used as, e.g., a turbine wheel for superchargers, engine bulb, or turbine blade for gas turbines.
Inventors:
WATANABE TAKANORI (JP)
IWAMURA HIDEAKI (JP)
NISHIKAWA KOJI (JP)
IWAMURA HIDEAKI (JP)
NISHIKAWA KOJI (JP)
Application Number:
PCT/JP2008/069585
Publication Date:
April 30, 2009
Filing Date:
October 22, 2008
Export Citation:
Assignee:
AIR WATER INC (JP)
WATANABE TAKANORI (JP)
IWAMURA HIDEAKI (JP)
NISHIKAWA KOJI (JP)
WATANABE TAKANORI (JP)
IWAMURA HIDEAKI (JP)
NISHIKAWA KOJI (JP)
International Classes:
C23C8/08; C22C14/00
Foreign References:
| JP2000087212A | 2000-03-28 | |||
| JPH0633172A | 1994-02-08 | |||
| JP2002332569A | 2002-11-22 | |||
| JP2005350743A | 2005-12-22 | |||
| JP2569712B2 | 1997-01-08 | |||
| JPH0633172A | 1994-02-08 | |||
| JPH0578817A | 1993-03-30 | |||
| JP2002332569A | 2002-11-22 | |||
| JP3358796B2 | 2002-12-24 | |||
| JPH06322509A | 1994-11-22 | |||
| JPH06322511A | 1994-11-22 |
Other References:
See also references of EP 2204466A4
Attorney, Agent or Firm:
MORIMOTO, Naoyuki (4-5 Tanimachi 2-chome, Chuo-ku, Osaka-sh, Osaka 12, JP)
Download PDF:
Previous Patent: BOUNDARY ESTIMATION APPARATUS AND METHOD
Next Patent: PEPTIDE VACCINE USING MIMIC MOLECULE OF AMYLOID β-PEPTIDE
Next Patent: PEPTIDE VACCINE USING MIMIC MOLECULE OF AMYLOID β-PEPTIDE