A crystal plasticity approach to understand fatigue response with respect to pores in additive manufactured aluminium alloys
File(s)
Published version
Author(s)
Cao, Mengzhen
Liu, Yang
Dunne, Fionn PE
Type
Journal Article
Abstract
A crystal plasticity finite element modelling method integrated with a stored energy density criterion is utilized to comparatively investigate fatigue crack nucleation behaviour and quantify fatigue life with respect to different pore types in AlSi10Mg fabricated by selective laser melting. Representative microstructural models show that fatigue crack nucleation exhibits high sensitivity to both gas/keyhole and lack of fusion pores, but particularly the latter, which leads to much lower fatigue life at high stress levels. Multi-intragranular slip system activations occurring at the sharp corners of lack of fusion pores contribute to substantial increase in local geometrically necessary dislocation density. Together with the rapid accumulation of slip, these drive high local stored energy density at the tips of lack of fusion pores. For gas/keyhole pores, high stresses lead to pore-induced shear band formation which shifts the origin of crack nucleation away from the pore to other microstructural features. At low stresses, fatigue life for lack of fusion and gas/keyhole pores tend to converge but remain shorter than for pore-free microstructures.
Date Issued
2022-08
Date Acceptance
2022-04-09
Citation
International Journal of Fatigue, 2022, 161
ISSN
0142-1123
Publisher
Elsevier
Journal / Book Title
International Journal of Fatigue
Volume
161
Copyright Statement
© 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000829856700003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=a2bf6146997ec60c407a63945d4e92bb
Subjects
Additive manufacturing
BEHAVIOR
CRACK NUCLEATION
Crystal Plasticity
CYCLE FATIGUE
DEFORMATION
DWELL FATIGUE
Engineering
Engineering, Mechanical
Fatigue crack nucleation
Fatigue life prediction
LASER
Materials Science
Materials Science, Multidisciplinary
METALLIC COMPONENTS
MICROSTRUCTURE
Pore
Science & Technology
STORED ENERGY
SURFACE
Technology
Publication Status
Published
Article Number
106917
Date Publish Online
2022-04-12