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 −300 MPa. 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.
Original language | English |
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Article number | 106025 |
Number of pages | 14 |
Journal | International Journal of Fatigue |
Volume | 143 |
Early online date | 1 Nov 2020 |
DOIs | |
Publication status | Published - Feb 2021 |
Bibliographical note
NOTICE: this is the author’s version of a work that was accepted for publication in International Journal of Fatigue. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Fatigue, 143 (2021)] DOI: 10.1016/j.ijfatigue.2020.106025© 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Copyright © and Moral Rights are retained by the author(s) and/ or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This item cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders.
Funder
Engineering and Physical Sciences Research Council (EPSRC), UK (Grant EP/N509747/1 )Keywords
- Aluminium alloys
- Fatigue initiation
- Micromechanics
- Surface flaws
ASJC Scopus subject areas
- Modelling and Simulation
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering
- Industrial and Manufacturing Engineering