Assessment of mixed mode loading on macroscopic fatigue crack paths in thick section Al-Cu-Li alloy plate
Assessment of mixed mode loading on macroscopic fatigue crack paths in thick section Al-Cu-Li alloy plate
High strength, wrought 7xxx (Al-Zn-Mg) and Al-Li based alloys show a propensity for fatigue macroscopic crack deflections aligned along grain boundaries. The present work reports a study on a 3rd generation Al-Li based alloy in the form of a thick AA2297 (Al-Cu-Li alloy) plate, where it was found that although the lithium containing material may indeed be more susceptible to mixed mode grain boundary failure (and by implication crack deflection in conventional tests), the AA2297 alloy fatigue behaviour is mechanistically and functionally equivalent to 7xxx alloy behaviour. It is shown that crack paths are controlled by a combination of crack loading mixity (KII/KI ratio) and maximum strain energy release rates (expressed as Keq.max). Increasing KII/KI ratio is seen to favour sustained grain boundary failure. Crack growth rate behaviour is discussed in terms of extrinsic and intrinsic components of crack growth resistance. It is shown that the present approach can be successfully applied to predict crack deflection / crack paths for a range of sample geometries and orientations on a range of high strength orthotropic aluminium alloys, including 3rd generation Al-Li based alloys and well-established 7xxx alloys)
379-387
Joyce, M.R.
e294d1ba-c37a-4149-b9c0-15095d643d3b
Starink, M.J.
fe61a323-4e0c-49c7-91f0-4450e1ec1e51
Sinclair, I.
6005f6c1-f478-434e-a52d-d310c18ade0d
2016
Joyce, M.R.
e294d1ba-c37a-4149-b9c0-15095d643d3b
Starink, M.J.
fe61a323-4e0c-49c7-91f0-4450e1ec1e51
Sinclair, I.
6005f6c1-f478-434e-a52d-d310c18ade0d
Joyce, M.R., Starink, M.J. and Sinclair, I.
(2016)
Assessment of mixed mode loading on macroscopic fatigue crack paths in thick section Al-Cu-Li alloy plate.
Materials & Design, 93, .
(doi:10.1016/j.matdes.2015.12.116).
Abstract
High strength, wrought 7xxx (Al-Zn-Mg) and Al-Li based alloys show a propensity for fatigue macroscopic crack deflections aligned along grain boundaries. The present work reports a study on a 3rd generation Al-Li based alloy in the form of a thick AA2297 (Al-Cu-Li alloy) plate, where it was found that although the lithium containing material may indeed be more susceptible to mixed mode grain boundary failure (and by implication crack deflection in conventional tests), the AA2297 alloy fatigue behaviour is mechanistically and functionally equivalent to 7xxx alloy behaviour. It is shown that crack paths are controlled by a combination of crack loading mixity (KII/KI ratio) and maximum strain energy release rates (expressed as Keq.max). Increasing KII/KI ratio is seen to favour sustained grain boundary failure. Crack growth rate behaviour is discussed in terms of extrinsic and intrinsic components of crack growth resistance. It is shown that the present approach can be successfully applied to predict crack deflection / crack paths for a range of sample geometries and orientations on a range of high strength orthotropic aluminium alloys, including 3rd generation Al-Li based alloys and well-established 7xxx alloys)
Text
Joyce et al 2016 Mater Des.pdf
- Accepted Manuscript
More information
e-pub ahead of print date: 31 December 2015
Published date: 2016
Organisations:
Engineering Mats & Surface Engineerg Gp
Identifiers
Local EPrints ID: 385249
URI: http://eprints.soton.ac.uk/id/eprint/385249
ISSN: 0261-3069
PURE UUID: c18aaf41-732b-4939-aeee-39315f338eac
Catalogue record
Date deposited: 11 Jan 2016 09:01
Last modified: 14 Mar 2024 22:13
Export record
Altmetrics
Contributors
Author:
M.R. Joyce
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics