Characterization of the nitrided γ-Ti-46Al–2Nb and γ-Ti-46Al–2Nb-0.7Cr-0.3Si intermetallic alloys

M. N. Mathabathe; A. S. Bolokang; G. Govender; C. W. Siyasiya; R. J. Mostert

doi:10.1016/j.matchemphys.2020.123703

Characterization of the nitrided γ-Ti-46Al–2Nb and γ-Ti-46Al–2Nb-0.7Cr-0.3Si intermetallic alloys

M. N. Mathabathe, A. S. Bolokang, G. Govender, C. W. Siyasiya, R. J. Mostert

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

6 Citations (Scopus)

Abstract

The thermal, surface properties and microstructures of the nitrided γ-Ti-46Al–2Nb and Ti–46Al–2Nb-0.7Cr-0.3Si intermetallic alloys were investigated. These vacuum-melted alloys were annealed at 1100 °C to stabilize the (α₂+γ) lamellae structure. Moreover, the annealed alloys were further annealed at 900 °C under nitrogen gas (nitridation). The alloys microstructures and nitride surface coatings were characterized. The Ti–46Al–2Nb alloy was comprised of γ-TiAl, α_2-Ti₃Al and β-phases after the annealing, while the Ti–46Al–2Nb-0.7Cr-0.7Si alloy revealed the Ti₅Si₃, γ-TiAl and α_2-Ti₃Al phases. Thin nitride layers formed on both alloys. After cyclic oxidation, the nitrided alloys exhibited surface spallation at different rates. The X-ray photoelectron spectroscopy (XPS) revealed the presence of mixed oxide layer of Al₂O₃, Cr₂O₃ and SiO₂ near the Ti–46Al–2Nb-0.7Cr-0.7Si surface.

Original language	English
Article number	123703
Journal	Materials Chemistry and Physics
Volume	257
DOIs	https://doi.org/10.1016/j.matchemphys.2020.123703
Publication status	Published - 1 Jan 2021
Externally published	Yes

Keywords

Cyclic oxidation
Intermetallics
Nitridation
XPS

ASJC Scopus subject areas

General Materials Science
Condensed Matter Physics

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10.1016/j.matchemphys.2020.123703

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title = "Characterization of the nitrided γ-Ti-46Al–2Nb and γ-Ti-46Al–2Nb-0.7Cr-0.3Si intermetallic alloys",

abstract = "The thermal, surface properties and microstructures of the nitrided γ-Ti-46Al–2Nb and Ti–46Al–2Nb-0.7Cr-0.3Si intermetallic alloys were investigated. These vacuum-melted alloys were annealed at 1100 °C to stabilize the (α2+γ) lamellae structure. Moreover, the annealed alloys were further annealed at 900 °C under nitrogen gas (nitridation). The alloys microstructures and nitride surface coatings were characterized. The Ti–46Al–2Nb alloy was comprised of γ-TiAl, α2-Ti3Al and β-phases after the annealing, while the Ti–46Al–2Nb-0.7Cr-0.7Si alloy revealed the Ti5Si3, γ-TiAl and α2-Ti3Al phases. Thin nitride layers formed on both alloys. After cyclic oxidation, the nitrided alloys exhibited surface spallation at different rates. The X-ray photoelectron spectroscopy (XPS) revealed the presence of mixed oxide layer of Al2O3, Cr2O3 and SiO2 near the Ti–46Al–2Nb-0.7Cr-0.7Si surface.",

keywords = "Cyclic oxidation, Intermetallics, Nitridation, XPS",

author = "Mathabathe, {M. N.} and Bolokang, {A. S.} and G. Govender and Siyasiya, {C. W.} and Mostert, {R. J.}",

note = "Publisher Copyright: {\textcopyright} 2020 Elsevier B.V.",

year = "2021",

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doi = "10.1016/j.matchemphys.2020.123703",

language = "English",

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T1 - Characterization of the nitrided γ-Ti-46Al–2Nb and γ-Ti-46Al–2Nb-0.7Cr-0.3Si intermetallic alloys

AU - Mathabathe, M. N.

AU - Bolokang, A. S.

AU - Govender, G.

AU - Siyasiya, C. W.

AU - Mostert, R. J.

PY - 2021/1/1

Y1 - 2021/1/1

N2 - The thermal, surface properties and microstructures of the nitrided γ-Ti-46Al–2Nb and Ti–46Al–2Nb-0.7Cr-0.3Si intermetallic alloys were investigated. These vacuum-melted alloys were annealed at 1100 °C to stabilize the (α2+γ) lamellae structure. Moreover, the annealed alloys were further annealed at 900 °C under nitrogen gas (nitridation). The alloys microstructures and nitride surface coatings were characterized. The Ti–46Al–2Nb alloy was comprised of γ-TiAl, α2-Ti3Al and β-phases after the annealing, while the Ti–46Al–2Nb-0.7Cr-0.7Si alloy revealed the Ti5Si3, γ-TiAl and α2-Ti3Al phases. Thin nitride layers formed on both alloys. After cyclic oxidation, the nitrided alloys exhibited surface spallation at different rates. The X-ray photoelectron spectroscopy (XPS) revealed the presence of mixed oxide layer of Al2O3, Cr2O3 and SiO2 near the Ti–46Al–2Nb-0.7Cr-0.7Si surface.

AB - The thermal, surface properties and microstructures of the nitrided γ-Ti-46Al–2Nb and Ti–46Al–2Nb-0.7Cr-0.3Si intermetallic alloys were investigated. These vacuum-melted alloys were annealed at 1100 °C to stabilize the (α2+γ) lamellae structure. Moreover, the annealed alloys were further annealed at 900 °C under nitrogen gas (nitridation). The alloys microstructures and nitride surface coatings were characterized. The Ti–46Al–2Nb alloy was comprised of γ-TiAl, α2-Ti3Al and β-phases after the annealing, while the Ti–46Al–2Nb-0.7Cr-0.7Si alloy revealed the Ti5Si3, γ-TiAl and α2-Ti3Al phases. Thin nitride layers formed on both alloys. After cyclic oxidation, the nitrided alloys exhibited surface spallation at different rates. The X-ray photoelectron spectroscopy (XPS) revealed the presence of mixed oxide layer of Al2O3, Cr2O3 and SiO2 near the Ti–46Al–2Nb-0.7Cr-0.7Si surface.

KW - Cyclic oxidation

KW - Intermetallics

KW - Nitridation

KW - XPS

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DO - 10.1016/j.matchemphys.2020.123703

M3 - Article

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ER -

Characterization of the nitrided γ-Ti-46Al–2Nb and γ-Ti-46Al–2Nb-0.7Cr-0.3Si intermetallic alloys

Abstract

Keywords

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