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Influence of Scanning Strategy on Residual Stresses in Laser-Based Powder Bed Fusion Manufactured Alloy 718 : Modeling and Experiments

Hassila, Carl Johan ; Malmelöv, Andreas ; Andersson, Carl ; Hektor, Johan ; Fisk, Martin LU ; Lundbäck, Andreas and Wiklund, Urban (2024) In Materials 17(24).
Abstract

In additive manufacturing, the presence of residual stresses in produced parts is a well-recognized phenomenon. These residual stresses not only elevate the risk of crack formation but also impose limitations on in-service performance. Moreover, it can distort printed parts if released, or in the worst case even cause a build to fail due to collision with the powder scraper. This study introduces a thermo-mechanical finite element model designed to predict the impact of various scanning strategies in order to mitigate the aforementioned unwanted outcomes. The investigation focuses on the deformation and residual stresses of two geometries manufactured by laser-based powder bed fusion (PBF-LB). To account for relaxation effects during... (More)

In additive manufacturing, the presence of residual stresses in produced parts is a well-recognized phenomenon. These residual stresses not only elevate the risk of crack formation but also impose limitations on in-service performance. Moreover, it can distort printed parts if released, or in the worst case even cause a build to fail due to collision with the powder scraper. This study introduces a thermo-mechanical finite element model designed to predict the impact of various scanning strategies in order to mitigate the aforementioned unwanted outcomes. The investigation focuses on the deformation and residual stresses of two geometries manufactured by laser-based powder bed fusion (PBF-LB). To account for relaxation effects during the process, a mechanism-based material model has been implemented and used. Additionally, a purely mechanical model, based on the inherent strain method, has been calibrated to account for different scanning strategies. To assess the predicted residual stresses, high-energy synchrotron measurements have been used to obtain values for comparison. The predictions of the models are evaluated, and their accuracy is discussed in terms of the physical aspects of the PBF-LB process. Both the thermo-mechanical models and the inherent strain method capture the trend of experimentally measured residual stress fields. While deformations are also adequately captured, there is an overall underprediction of their magnitude. This work contributes to advancing our understanding of the thermo-mechanical behavior in PBF-LB and provides valuable insights for optimizing scanning strategies in additive manufacturing processes.

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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
EBSD, finite element method, inherent strain, LPBF, mechanism-based material model, PBF-LB, synchrotron diffraction, validation
in
Materials
volume
17
issue
24
article number
6265
publisher
MDPI AG
external identifiers
  • pmid:39769864
  • scopus:85213293326
ISSN
1996-1944
DOI
10.3390/ma17246265
language
English
LU publication?
yes
id
72678e60-3cb8-4a4b-9bfe-30e0c9c74932
date added to LUP
2025-01-16 13:50:45
date last changed
2025-07-04 04:10:10
@article{72678e60-3cb8-4a4b-9bfe-30e0c9c74932,
  abstract     = {{<p>In additive manufacturing, the presence of residual stresses in produced parts is a well-recognized phenomenon. These residual stresses not only elevate the risk of crack formation but also impose limitations on in-service performance. Moreover, it can distort printed parts if released, or in the worst case even cause a build to fail due to collision with the powder scraper. This study introduces a thermo-mechanical finite element model designed to predict the impact of various scanning strategies in order to mitigate the aforementioned unwanted outcomes. The investigation focuses on the deformation and residual stresses of two geometries manufactured by laser-based powder bed fusion (PBF-LB). To account for relaxation effects during the process, a mechanism-based material model has been implemented and used. Additionally, a purely mechanical model, based on the inherent strain method, has been calibrated to account for different scanning strategies. To assess the predicted residual stresses, high-energy synchrotron measurements have been used to obtain values for comparison. The predictions of the models are evaluated, and their accuracy is discussed in terms of the physical aspects of the PBF-LB process. Both the thermo-mechanical models and the inherent strain method capture the trend of experimentally measured residual stress fields. While deformations are also adequately captured, there is an overall underprediction of their magnitude. This work contributes to advancing our understanding of the thermo-mechanical behavior in PBF-LB and provides valuable insights for optimizing scanning strategies in additive manufacturing processes.</p>}},
  author       = {{Hassila, Carl Johan and Malmelöv, Andreas and Andersson, Carl and Hektor, Johan and Fisk, Martin and Lundbäck, Andreas and Wiklund, Urban}},
  issn         = {{1996-1944}},
  keywords     = {{EBSD; finite element method; inherent strain; LPBF; mechanism-based material model; PBF-LB; synchrotron diffraction; validation}},
  language     = {{eng}},
  number       = {{24}},
  publisher    = {{MDPI AG}},
  series       = {{Materials}},
  title        = {{Influence of Scanning Strategy on Residual Stresses in Laser-Based Powder Bed Fusion Manufactured Alloy 718 : Modeling and Experiments}},
  url          = {{http://dx.doi.org/10.3390/ma17246265}},
  doi          = {{10.3390/ma17246265}},
  volume       = {{17}},
  year         = {{2024}},
}