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Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression

Tutkimustuotosvertaisarvioitu

Standard

Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression. / Edwards, Thomas Edward James; Di Gioacchino, Fabio; Goodfellow, Amy Jane; Mohanty, Gaurav; Wehrs, Juri; Michler, Johann; Clegg, William John.

julkaisussa: Acta Materialia, Vuosikerta 166, 01.03.2019, s. 85-99.

Tutkimustuotosvertaisarvioitu

Harvard

Edwards, TEJ, Di Gioacchino, F, Goodfellow, AJ, Mohanty, G, Wehrs, J, Michler, J & Clegg, WJ 2019, 'Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression', Acta Materialia, Vuosikerta. 166, Sivut 85-99. https://doi.org/10.1016/j.actamat.2018.11.050

APA

Edwards, T. E. J., Di Gioacchino, F., Goodfellow, A. J., Mohanty, G., Wehrs, J., Michler, J., & Clegg, W. J. (2019). Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression. Acta Materialia, 166, 85-99. https://doi.org/10.1016/j.actamat.2018.11.050

Vancouver

Edwards TEJ, Di Gioacchino F, Goodfellow AJ, Mohanty G, Wehrs J, Michler J et al. Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression. Acta Materialia. 2019 maalis 1;166:85-99. https://doi.org/10.1016/j.actamat.2018.11.050

Author

Edwards, Thomas Edward James ; Di Gioacchino, Fabio ; Goodfellow, Amy Jane ; Mohanty, Gaurav ; Wehrs, Juri ; Michler, Johann ; Clegg, William John. / Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression. Julkaisussa: Acta Materialia. 2019 ; Vuosikerta 166. Sivut 85-99.

Bibtex - Lataa

@article{9d4f7e89c56f493b86ef33141c66f110,
title = "Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression",
abstract = "The distribution of strain in hard mode oriented lamellar stacks of the two-phase γ-TiAl/α2-Ti3Al alloy Ti-45Al-2Nb-2Mn (at.{\%})-0.8 vol{\%} TiB2 was measured at several temperatures up to 633 °C by in situ micropillar compression, complemented by electron backscatter diffraction orientation mapping and digital image correlation strain mapping of a thermally stable surface Pt speckle pattern. Post-mortem transmission electron microscopy further identified the finest scale deformation structures. It was found that slip and twinning transverse to the lamellae operates within discreet bands that zigzag across the lamellar structure. The shear strain within each band is approximately constant across the pillar width. This is inconsistent with current energetic models for transverse twin formation in γ-TiAl, which assume independent, non-interacting twins. This is explained using a mathematical formulation for the stress required to operate this transverse mechanical twinning as a function of strain. This study has elucidated how the multi-scale combination of several transverse twinning systems on different {111} planes in γ-TiAl lamellae can relieve the elastic stresses generated at a lamellar interface by the primary (highest Schmid factor) twinning system. It is thought that the facilitation of this mechanism will promote the ductilisation of lamellar γ-TiAl alloys. This is crucial for an increased damage tolerance and ease of component manufacture, leading to a more widespread use of γ-TiAl alloys.",
keywords = "Deformation twinning, Digital image correlation, Electron backscattering diffraction (EBSD), Scanning transmission electron microscopy, Titanium aluminide polysynthetically twinned crystal (PST)",
author = "Edwards, {Thomas Edward James} and {Di Gioacchino}, Fabio and Goodfellow, {Amy Jane} and Gaurav Mohanty and Juri Wehrs and Johann Michler and Clegg, {William John}",
year = "2019",
month = "3",
day = "1",
doi = "10.1016/j.actamat.2018.11.050",
language = "English",
volume = "166",
pages = "85--99",
journal = "Acta Materialia",
issn = "1359-6454",
publisher = "Elsevier",

}

RIS (suitable for import to EndNote) - Lataa

TY - JOUR

T1 - Transverse deformation of a lamellar TiAl alloy at high temperature by in situ microcompression

AU - Edwards, Thomas Edward James

AU - Di Gioacchino, Fabio

AU - Goodfellow, Amy Jane

AU - Mohanty, Gaurav

AU - Wehrs, Juri

AU - Michler, Johann

AU - Clegg, William John

PY - 2019/3/1

Y1 - 2019/3/1

N2 - The distribution of strain in hard mode oriented lamellar stacks of the two-phase γ-TiAl/α2-Ti3Al alloy Ti-45Al-2Nb-2Mn (at.%)-0.8 vol% TiB2 was measured at several temperatures up to 633 °C by in situ micropillar compression, complemented by electron backscatter diffraction orientation mapping and digital image correlation strain mapping of a thermally stable surface Pt speckle pattern. Post-mortem transmission electron microscopy further identified the finest scale deformation structures. It was found that slip and twinning transverse to the lamellae operates within discreet bands that zigzag across the lamellar structure. The shear strain within each band is approximately constant across the pillar width. This is inconsistent with current energetic models for transverse twin formation in γ-TiAl, which assume independent, non-interacting twins. This is explained using a mathematical formulation for the stress required to operate this transverse mechanical twinning as a function of strain. This study has elucidated how the multi-scale combination of several transverse twinning systems on different {111} planes in γ-TiAl lamellae can relieve the elastic stresses generated at a lamellar interface by the primary (highest Schmid factor) twinning system. It is thought that the facilitation of this mechanism will promote the ductilisation of lamellar γ-TiAl alloys. This is crucial for an increased damage tolerance and ease of component manufacture, leading to a more widespread use of γ-TiAl alloys.

AB - The distribution of strain in hard mode oriented lamellar stacks of the two-phase γ-TiAl/α2-Ti3Al alloy Ti-45Al-2Nb-2Mn (at.%)-0.8 vol% TiB2 was measured at several temperatures up to 633 °C by in situ micropillar compression, complemented by electron backscatter diffraction orientation mapping and digital image correlation strain mapping of a thermally stable surface Pt speckle pattern. Post-mortem transmission electron microscopy further identified the finest scale deformation structures. It was found that slip and twinning transverse to the lamellae operates within discreet bands that zigzag across the lamellar structure. The shear strain within each band is approximately constant across the pillar width. This is inconsistent with current energetic models for transverse twin formation in γ-TiAl, which assume independent, non-interacting twins. This is explained using a mathematical formulation for the stress required to operate this transverse mechanical twinning as a function of strain. This study has elucidated how the multi-scale combination of several transverse twinning systems on different {111} planes in γ-TiAl lamellae can relieve the elastic stresses generated at a lamellar interface by the primary (highest Schmid factor) twinning system. It is thought that the facilitation of this mechanism will promote the ductilisation of lamellar γ-TiAl alloys. This is crucial for an increased damage tolerance and ease of component manufacture, leading to a more widespread use of γ-TiAl alloys.

KW - Deformation twinning

KW - Digital image correlation

KW - Electron backscattering diffraction (EBSD)

KW - Scanning transmission electron microscopy

KW - Titanium aluminide polysynthetically twinned crystal (PST)

U2 - 10.1016/j.actamat.2018.11.050

DO - 10.1016/j.actamat.2018.11.050

M3 - Article

VL - 166

SP - 85

EP - 99

JO - Acta Materialia

JF - Acta Materialia

SN - 1359-6454

ER -