Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Anisotropic fatigue properties of Alloy 718 manufactured by Electron Beam Powder Bed Fusion
University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. (PTW)ORCID iD: 0000-0002-8664-4573
University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. Linköping University, Department of Management and Engineering, Linköping, 58183, Sweden. (PTW)ORCID iD: 0000-0002-8304-0221
University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. GKN Aerospace Sweden AB, Trollhättan, 46181, Sweden. (PTW)
University West, Department of Engineering Science, Division of Subtractive and Additive Manufacturing. (PTW)ORCID iD: 0000-0002-7675-7152
2020 (English)In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 141, article id 105898Article in journal (Refereed) Published
Abstract [en]

In this study, Alloy 718 specimens manufactured by Electron Beam Powder Bed Fusion process are subjected to two different post-treatments to have different microstructural features. Low cycle fatigue testing has been performed both parallel and transverse to the build direction. EB-PBF Alloy 718 exhibits anisotropic fatigue behaviour; the fatigue life is better along the parallel direction compared to the transverse direction. The anisotropy in fatigue life is related to the anisotropy in the Young’s modulus. The pseudo-elastic stress vs. fatigue life approach is presented as a potential solution to handle anisotropy in fatigue life assessment of additively manufactured engineering components. © 2020 The Authors

Place, publisher, year, edition, pages
Elsevier, 2020. Vol. 141, article id 105898
Keywords [en]
Anisotropy; Elastic moduli; Electron beams; Fatigue testing, Build direction; Engineering components; Fatigue behaviour; Fatigue life assessment; Fatigue properties; Low cycle fatigue testing; Microstructural features; Post treatment, Fatigue of materials
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
URN: urn:nbn:se:hv:diva-15776DOI: 10.1016/j.ijfatigue.2020.105898ISI: 000571197300001Scopus ID: 2-s2.0-85089796084OAI: oai:DiVA.org:hv-15776DiVA, id: diva2:1465128
Funder
Knowledge Foundation, 20160281Available from: 2020-09-08 Created: 2020-09-08 Last updated: 2020-11-16Bibliographically approved
In thesis
1. Towards understanding the fatigue behaviour of Alloy 718 manufactured by Powder Bed Fusion processes
Open this publication in new window or tab >>Towards understanding the fatigue behaviour of Alloy 718 manufactured by Powder Bed Fusion processes
2020 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Additive Manufacturing (AM) is a disruptive modern manufacturing process in which parts are manufactured in a layer-wise fashion. Among the metal AM processes, Powder Bed Fusion (PBF) technology — comprised of Electron Beam Powder Bed Fusion (EB-PBF) and Laser Beam Powder Bed Fusion (LB-PBF) —has opened up a design space that was formerly unavailable with conventionalmanufacturing processes. PBF processes offer several advantages; however, thesuitability of these processes to replace the conventional processes must be investigatedin detail. Therefore, understanding the AM process – post-processing –microstructure – property relationships is crucial for the manufacturing of high performance components. In this regard, only limited work has been done towards understanding the fatigue behaviour of PBF Alloy 718. The aim of this work, therefore, is to understand how the fatigue behaviour of PBF Alloy 718 is affected by its microstructure. Besides, the influence of the rough as-built surface is also investigated. In general, the <100> fibre texture along the build direction that resulted from PBF processing of Alloy 718 led to anisotropy in Young's modulus. Consequently,the fatigue performance under controlled amplitudes of strain was anisotropic such that the low-modulus direction had longer fatigue life and vice versa. This texture-induced elasticity-dependent anisotropic strain-life behaviour couldbe normalized by the pseudo-elastic stress vs fatigue life approach.Inclusions and defects had a detrimental effect on fatigue performance. Numerousfactors, such as their geometry, volume fraction, and distribution, determinedthe effect on fatigue behaviour. Hot Isostatic Pressing (HIP) eliminated most defect sand led to an improvement in fatigue performance. However, HIP did not alter the inclusions, which acted as crack initiation sites and reduced fatigue life. The rough as-built surface, which had numerous notch-like crack initiation sites, deteriorated fatigue performance; however, it lowered the scatter in fatigue life. Machining off the as-built surface improved fatigue life but increased the scatter.

Place, publisher, year, edition, pages
Trollhättan: University West, 2020. p. 79
Series
PhD Thesis: University West ; 42
Keywords
Fatigue; Additive Manufacturing; Powder Bed Fusion; Superalloy; Microstructure; Surface Roughness
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-16034 (URN)978-91-88847-79-9 (ISBN)978-91-88847-78-2 (ISBN)
Public defence
2020-12-08, Albertssalen, Trollhättan, 13:00 (English)
Opponent
Supervisors
Note

Tillstånd till elektronisk publicering finns för samtliga artiklar

Available from: 2020-11-16 Created: 2020-11-16 Last updated: 2020-11-16Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records

Balachandramurthi, Arun RamanathanMoverare, JohanHansson, ThomasPederson, Robert

Search in DiVA

By author/editor
Balachandramurthi, Arun RamanathanMoverare, JohanHansson, ThomasPederson, Robert
By organisation
Division of Subtractive and Additive Manufacturing
In the same journal
International Journal of Fatigue
Manufacturing, Surface and Joining Technology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 121 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf