Effects of laser shock peening on the mechanisms of fatigue short crack initiation and propagation of AA7075-T651
Effects of laser shock peening on the mechanisms of fatigue short crack initiation and propagation of AA7075-T651
A laser shock peening (LSP) treatment was performed on AA7075-T651 for maximum fatigue improvement. Surface and microstructural characterisation techniques (micro-hardness, SEM-EBSD, contact-profilometry) showed LSP surface modification was limited, and LSP generated deep compressive residual stresses above -300MPa. Fatigue testing showed a two-order magnitude increase in overall life, due to the mechanism of crack initiation changing from surface second-phase particles to subsurface crack initiation dependent on the local stress field. Modelling highlights the sensitive balance between surface roughness (including LSP-induced pits) and residual stress on the micro-mechanism of crack initiation, and how this can be used to maximise fatigue life extension.
Aluminium alloys, Fatigue initiation, Micromechanics, Surface flaws
1-14
Sanchez Araujo, Alvaro Gonzalo
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You, Chao
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Leering, Mitchell
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Glaser, Daniel
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Furfari, Domenico
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Fitzpatrick, M.E.
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Wharton, Julian
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Reed, Philippa
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1 February 2021
Sanchez Araujo, Alvaro Gonzalo
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You, Chao
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Leering, Mitchell
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Glaser, Daniel
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Furfari, Domenico
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Fitzpatrick, M.E.
26eb385f-4b65-4f9c-86fc-6c2464f9fc1e
Wharton, Julian
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Reed, Philippa
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Sanchez Araujo, Alvaro Gonzalo, You, Chao, Leering, Mitchell, Glaser, Daniel, Furfari, Domenico, Fitzpatrick, M.E., Wharton, Julian and Reed, Philippa
(2021)
Effects of laser shock peening on the mechanisms of fatigue short crack initiation and propagation of AA7075-T651.
International Journal of Fatigue, 143, , [106025].
(doi:10.1016/j.ijfatigue.2020.106025).
Abstract
A laser shock peening (LSP) treatment was performed on AA7075-T651 for maximum fatigue improvement. Surface and microstructural characterisation techniques (micro-hardness, SEM-EBSD, contact-profilometry) showed LSP surface modification was limited, and LSP generated deep compressive residual stresses above -300MPa. Fatigue testing showed a two-order magnitude increase in overall life, due to the mechanism of crack initiation changing from surface second-phase particles to subsurface crack initiation dependent on the local stress field. Modelling highlights the sensitive balance between surface roughness (including LSP-induced pits) and residual stress on the micro-mechanism of crack initiation, and how this can be used to maximise fatigue life extension.
Text
Effects of laser shock peening on the mechanisms of fatigue short crack initiation and propagation of AA7075-T651
- Accepted Manuscript
More information
Accepted/In Press date: 27 October 2020
e-pub ahead of print date: 1 November 2020
Published date: 1 February 2021
Additional Information:
Funding Information:
This study is financially supported by the Engineering and Physical Sciences Research Council (EPSRC), UK (Grant EP/N509747/1). The authors would like to acknowledge the funding and support of the University of Southampton. The support of Coventry University for performing residual stress analysis and providing laser shock peening expertise. The Council of Scientific and Industrial Research (CSIR) of South Africa for access to laser shock peening equipment and expertise. The financial support and sponsorship by Airbus Operations GmbH. Michael E. Fitzpatrick is grateful for funding from the Lloyd's Register Foundation, a charitable foundation helping protect life and property by supporting engineering-related education, public engagement, and the application of research. All data supporting this study are openly available from the University of Southampton repository at https://doi.org/10.5258/SOTON/D1616.
Funding Information:
This study is financially supported by the Engineering and Physical Sciences Research Council (EPSRC), UK (Grant EP/N509747/1 ). The authors would like to acknowledge the funding and support of the University of Southampton. The support of Coventry University for performing residual stress analysis and providing laser shock peening expertise. The Council of Scientific and Industrial Research (CSIR) of South Africa for access to laser shock peening equipment and expertise. The financial support and sponsorship by Airbus Operations GmbH.
Funding Information:
Michael E. Fitzpatrick is grateful for funding from the Lloyd’s Register Foundation, a charitable foundation helping protect life and property by supporting engineering-related education, public engagement, and the application of research.
Publisher Copyright:
© 2020 Elsevier Ltd
Keywords:
Aluminium alloys, Fatigue initiation, Micromechanics, Surface flaws
Identifiers
Local EPrints ID: 444912
URI: http://eprints.soton.ac.uk/id/eprint/444912
ISSN: 0142-1123
PURE UUID: e5a3c2b6-0452-4582-9e8d-66f0b88b654b
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Date deposited: 11 Nov 2020 17:31
Last modified: 17 Mar 2024 06:03
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Contributors
Author:
Alvaro Gonzalo Sanchez Araujo
Author:
Chao You
Author:
Mitchell Leering
Author:
Daniel Glaser
Author:
Domenico Furfari
Author:
M.E. Fitzpatrick
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