An analysis of fatigue failure mechanisms in an additively manufactured and shot peened IN 718 nickel superalloy
The family of additive manufacturing techniques has been attracting significant attention of manufacturers and researchers, due to its unrivalled flexibility to fabricate and repair geometrically complex objects. However, material shaping is not sufficient: wide adoption of additive manufacturing ca...
Main Authors: | , , , , |
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Format: | Journal article |
Language: | English |
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Elsevier
2020
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_version_ | 1797075606967418880 |
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author | Salvati, E Lunt, AJG Heason, CP Baxter, GJ Korsunsky, AM |
author_facet | Salvati, E Lunt, AJG Heason, CP Baxter, GJ Korsunsky, AM |
author_sort | Salvati, E |
collection | OXFORD |
description | The family of additive manufacturing techniques has been attracting significant attention of manufacturers and researchers, due to its unrivalled flexibility to fabricate and repair geometrically complex objects. However, material shaping is not sufficient: wide adoption of additive manufacturing can only occur upon the achievement of satisfactory mechanical performance in terms of structural integrity. The present study exploits a wide range of micro-scale experimental techniques to shed light on fatigue failure mechanisms of Laser Metal Deposition IN718 Ni-base superalloy, and to study the effect of shot peening treatment. Thorough microstructural and fractographic analyses revealed the main deformation mechanism associated with twinning during crack propagation, while crack initiation was found to be promoted by both slip system deformation and twinning around microstructural defects, rather than at sample free-surfaces. It was found that precipitates played a major role in determining the deformation mode. It was discovered that in this case-study, shot-peening residual stresses may have a detrimental effect, in view of the presence of the largest defects within a region where tensile residual stress was present. The results presented here improve understanding of failure mechanisms and thus define future directions of development for manufacture optimisation. |
first_indexed | 2024-03-06T23:52:41Z |
format | Journal article |
id | oxford-uuid:73276265-7d44-4eb5-bb91-a017b34afbe6 |
institution | University of Oxford |
language | English |
last_indexed | 2024-03-06T23:52:41Z |
publishDate | 2020 |
publisher | Elsevier |
record_format | dspace |
spelling | oxford-uuid:73276265-7d44-4eb5-bb91-a017b34afbe62022-03-26T19:54:33ZAn analysis of fatigue failure mechanisms in an additively manufactured and shot peened IN 718 nickel superalloyJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:73276265-7d44-4eb5-bb91-a017b34afbe6EnglishSymplectic ElementsElsevier 2020Salvati, ELunt, AJGHeason, CPBaxter, GJKorsunsky, AMThe family of additive manufacturing techniques has been attracting significant attention of manufacturers and researchers, due to its unrivalled flexibility to fabricate and repair geometrically complex objects. However, material shaping is not sufficient: wide adoption of additive manufacturing can only occur upon the achievement of satisfactory mechanical performance in terms of structural integrity. The present study exploits a wide range of micro-scale experimental techniques to shed light on fatigue failure mechanisms of Laser Metal Deposition IN718 Ni-base superalloy, and to study the effect of shot peening treatment. Thorough microstructural and fractographic analyses revealed the main deformation mechanism associated with twinning during crack propagation, while crack initiation was found to be promoted by both slip system deformation and twinning around microstructural defects, rather than at sample free-surfaces. It was found that precipitates played a major role in determining the deformation mode. It was discovered that in this case-study, shot-peening residual stresses may have a detrimental effect, in view of the presence of the largest defects within a region where tensile residual stress was present. The results presented here improve understanding of failure mechanisms and thus define future directions of development for manufacture optimisation. |
spellingShingle | Salvati, E Lunt, AJG Heason, CP Baxter, GJ Korsunsky, AM An analysis of fatigue failure mechanisms in an additively manufactured and shot peened IN 718 nickel superalloy |
title | An analysis of fatigue failure mechanisms in an additively manufactured and shot peened IN 718 nickel superalloy |
title_full | An analysis of fatigue failure mechanisms in an additively manufactured and shot peened IN 718 nickel superalloy |
title_fullStr | An analysis of fatigue failure mechanisms in an additively manufactured and shot peened IN 718 nickel superalloy |
title_full_unstemmed | An analysis of fatigue failure mechanisms in an additively manufactured and shot peened IN 718 nickel superalloy |
title_short | An analysis of fatigue failure mechanisms in an additively manufactured and shot peened IN 718 nickel superalloy |
title_sort | analysis of fatigue failure mechanisms in an additively manufactured and shot peened in 718 nickel superalloy |
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