Environmental embrittlement of a third generation γ TiAl alloy

S. L. Draper; D. Isheim

doi:10.1016/j.intermet.2011.10.006

Environmental embrittlement of a third generation γ TiAl alloy

S. L. Draper^*, D. Isheim

^*Corresponding author for this work

Materials Science and Engineering

Research output: Contribution to journal › Article › peer-review

30 Scopus citations

Abstract

Exposure of a Ti-45Al-5Nb alloy to elevated temperatures has been shown to result in a loss of ductility resulting from a near surface effect involving diffusion of oxygen into the alloy. Local electrode atom probe analysis was conducted at 2, 13, and 25 μm distance from the oxide/base-metal interface. Oxygen was preferentially located in the α ₂ phase with concentrations up to 14.8 at.% and diminishing with increasing distance from the surface. Near surface microstructural changes were only visible up to 10 μm from the surface but the oxygen diffusion significantly exceeded that distance. The diffusion coefficient of oxygen into the α ₂ phase was estimated based on the oxygen concentrations obtained from local electrode atom probe analysis. Fluorine ion implantation on the surface was investigated as a possible solution to the embrittlement.

Original language	English (US)
Pages (from-to)	77-83
Number of pages	7
Journal	Intermetallics
Volume	22
DOIs	https://doi.org/10.1016/j.intermet.2011.10.006
State	Published - Mar 2012

Keywords

A. Titanium aluminides, based on TiAl
B. Diffusion
B. Environmental embrittlement
B. Surface properties
F. Atom probe
F. Microprobe

ASJC Scopus subject areas

Chemistry(all)
Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/j.intermet.2011.10.006

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title = "Environmental embrittlement of a third generation γ TiAl alloy",

abstract = "Exposure of a Ti-45Al-5Nb alloy to elevated temperatures has been shown to result in a loss of ductility resulting from a near surface effect involving diffusion of oxygen into the alloy. Local electrode atom probe analysis was conducted at 2, 13, and 25 μm distance from the oxide/base-metal interface. Oxygen was preferentially located in the α 2 phase with concentrations up to 14.8 at.% and diminishing with increasing distance from the surface. Near surface microstructural changes were only visible up to 10 μm from the surface but the oxygen diffusion significantly exceeded that distance. The diffusion coefficient of oxygen into the α 2 phase was estimated based on the oxygen concentrations obtained from local electrode atom probe analysis. Fluorine ion implantation on the surface was investigated as a possible solution to the embrittlement.",

keywords = "A. Titanium aluminides, based on TiAl, B. Diffusion, B. Environmental embrittlement, B. Surface properties, F. Atom probe, F. Microprobe",

author = "Draper, {S. L.} and D. Isheim",

note = "Funding Information: The authors are grateful to David Hull, NASA Glenn Research Center, for the electron microprobe analysis and A. Donchev, Karl-Winnacker-Institut, of the DECHEMA e.V., for the F ion implantation. The Atom-probe tomographic measurements were performed at the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The LEAP tomograph was purchased and upgraded with funding from NSF-MRI ( DMR-0420532 ) and ONR-DURIP ( N00014-0400798 , N00014-0610539 , N00014-0910781 ) grants. The authors are thankful to Stephan Gerstl at Imago Scientific Instruments for LEAP analysis of bulk alloy.",

year = "2012",

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doi = "10.1016/j.intermet.2011.10.006",

language = "English (US)",

volume = "22",

pages = "77--83",

journal = "Intermetallics",

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AU - Draper, S. L.

AU - Isheim, D.

N1 - Funding Information: The authors are grateful to David Hull, NASA Glenn Research Center, for the electron microprobe analysis and A. Donchev, Karl-Winnacker-Institut, of the DECHEMA e.V., for the F ion implantation. The Atom-probe tomographic measurements were performed at the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The LEAP tomograph was purchased and upgraded with funding from NSF-MRI ( DMR-0420532 ) and ONR-DURIP ( N00014-0400798 , N00014-0610539 , N00014-0910781 ) grants. The authors are thankful to Stephan Gerstl at Imago Scientific Instruments for LEAP analysis of bulk alloy.

PY - 2012/3

Y1 - 2012/3

N2 - Exposure of a Ti-45Al-5Nb alloy to elevated temperatures has been shown to result in a loss of ductility resulting from a near surface effect involving diffusion of oxygen into the alloy. Local electrode atom probe analysis was conducted at 2, 13, and 25 μm distance from the oxide/base-metal interface. Oxygen was preferentially located in the α 2 phase with concentrations up to 14.8 at.% and diminishing with increasing distance from the surface. Near surface microstructural changes were only visible up to 10 μm from the surface but the oxygen diffusion significantly exceeded that distance. The diffusion coefficient of oxygen into the α 2 phase was estimated based on the oxygen concentrations obtained from local electrode atom probe analysis. Fluorine ion implantation on the surface was investigated as a possible solution to the embrittlement.

AB - Exposure of a Ti-45Al-5Nb alloy to elevated temperatures has been shown to result in a loss of ductility resulting from a near surface effect involving diffusion of oxygen into the alloy. Local electrode atom probe analysis was conducted at 2, 13, and 25 μm distance from the oxide/base-metal interface. Oxygen was preferentially located in the α 2 phase with concentrations up to 14.8 at.% and diminishing with increasing distance from the surface. Near surface microstructural changes were only visible up to 10 μm from the surface but the oxygen diffusion significantly exceeded that distance. The diffusion coefficient of oxygen into the α 2 phase was estimated based on the oxygen concentrations obtained from local electrode atom probe analysis. Fluorine ion implantation on the surface was investigated as a possible solution to the embrittlement.

KW - A. Titanium aluminides, based on TiAl

KW - B. Diffusion

KW - B. Environmental embrittlement

KW - B. Surface properties

KW - F. Atom probe

KW - F. Microprobe

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JO - Intermetallics

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ER -

Environmental embrittlement of a third generation γ TiAl alloy

Abstract

Keywords

ASJC Scopus subject areas

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