Influence of complex LCF and dwell load regimes on fatigue of Ti–6Al–4V
File(s)
Accepted version
Author(s)
Tympel, PO
Lindley, TC
Saunders, EA
Dixon, M
Dye, D
Type
Journal Article
Abstract
Real components are usually subjected to variable amplitude fatigue, and yet the deformation micromechanisms that occur due to such load changes have barely been the subject of study. Here, unidirectionally rolled equiaxed Ti–6Al–4V plate was subjected to mixed dwell and variable amplitude low cycle fatigue (LCF), with the finding that overloads near the yield stress were found to retard subsequent fatigue crack growth, whilst elastic underloads were found to accelerate subsequent growth. Dwell intervals were found to be especially damaging, to a far greater extent than either dwell or LCF alone. Dwell facets were found to initiate subsurface and to be smoother than LCF facets, but were otherwise similar in orientation (∼30° to the loading axis) and crystallographic plane, 2–13° from (0002). However, no alteration of the slip bands underlying striations was observed at the point of load changes using TEM. In failure investigation, striation counting is an important tool; the loading changes used were not found to affect the number of striations formed. Dislocation networks were found between similarly oriented grains in the as-received material, which disintegrated under dwell loading and at high stresses.
Date Issued
2016-01-15
Date Acceptance
2015-09-08
Citation
Acta Materialia, 2016, 103 (1), pp.77-88
ISSN
1359-6454
Publisher
Elsevier
Start Page
77
End Page
88
Journal / Book Title
Acta Materialia
Volume
103
Issue
1
Copyright Statement
© 2015, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Identifier
https://www.sciencedirect.com/science/article/pii/S1359645415006801
Grant Number
EP/H004882/1
EP/K034332/1
EP/E044700/1
Subjects
Science & Technology
Technology
Materials Science, Multidisciplinary
Metallurgy & Metallurgical Engineering
Materials Science
Titanium alloys
Fatigue
Facets
TEM
Dislocation structures
NEAR-ALPHA TITANIUM
CRACK GROWTH-BEHAVIOR
HIGH-CYCLE FATIGUE
DISLOCATION INTERACTIONS
SENSITIVE FATIGUE
SINGLE-CRYSTALS
FRACTURE FACETS
STRESS RATIO
ALLOY
MECHANISMS
Materials
0204 Condensed Matter Physics
0912 Materials Engineering
0913 Mechanical Engineering
Notes
publisher: Elsevier articletitle: Influence of complex LCF and dwell load regimes on fatigue of Ti–6Al–4V journaltitle: Acta Materialia articlelink: http://dx.doi.org/10.1016/j.actamat.2015.09.014 content_type: article copyright: Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Publication Status
Published
Date Publish Online
2015-11-06