Linkage of Macro- and Microscale Modeling Tools for Additive Manufacturing of Steels

Additive manufacturing (AM) offers several benefits including the capability to produce unique microstructures, geometrical freedom allowing for material and energy savings, and easy production lines with fewer post-processing steps. However, AM processes are complex and phenomena occurring at diffe...

Full description

Bibliographic Details
Main Authors: Julia Sjöström, A. Durga, Greta Lindwall
Format: Article
Language:English
Published: Frontiers Media S.A. 2022-05-01
Series:Frontiers in Materials
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fmats.2022.797226/full
_version_ 1817986222950187008
author Julia Sjöström
Julia Sjöström
A. Durga
Greta Lindwall
author_facet Julia Sjöström
Julia Sjöström
A. Durga
Greta Lindwall
author_sort Julia Sjöström
collection DOAJ
description Additive manufacturing (AM) offers several benefits including the capability to produce unique microstructures, geometrical freedom allowing for material and energy savings, and easy production lines with fewer post-processing steps. However, AM processes are complex and phenomena occurring at different length and time scales need to be understood and controlled to avoid challenges with, for example, defects, residual stresses, distortions, and alloy restrictions. To overcome some of these challenges and to have more control over the final product, computational tools for different length scales need to be combined. In this work, an 18Ni300 maraging steel part is studied to understand the link between the process parameters and the as-built microstructure. The temperature evolution during laser powder bed fusion is simulated using the MSC simulation software Simufact Additive. This result is then linked to microscale models within the Thermo-Calc software package to predict the elemental micro-segregation, martensite start (Ms) temperature, and martensite fraction. The different values of the key process parameters such as laser speed, laser power, heating efficiency, and baseplate temperature are considered, leading to different thermal histories. The thermal histories affect the elemental segregation across the solidification structure, which in turn results in different Ms temperatures at different locations of the built part. It is found that higher laser energy generally causes higher temperatures and higher cooling rates, which results in a larger degree of elemental segregation and lower Ms temperatures in segregated regions. Furthermore, the segregated regions are predicted to have Ms temperatures below 200°C, which would result in retained austenite when using a baseplate temperature of 200°C. On the other hand, by using a baseplate temperature of 100°C, all regions would reach temperatures below the Ms temperature, and an almost fully martensitic structure would be possible. In summary, it is demonstrated how the linkage of macro- and microscale modeling tools for AM can be used to optimize the process and produce the desired microstructure, thereby achieving the desired mechanical properties.
first_indexed 2024-04-14T00:07:38Z
format Article
id doaj.art-513860e27a604f5e8e0f8ae4dd1e365e
institution Directory Open Access Journal
issn 2296-8016
language English
last_indexed 2024-04-14T00:07:38Z
publishDate 2022-05-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Materials
spelling doaj.art-513860e27a604f5e8e0f8ae4dd1e365e2022-12-22T02:23:29ZengFrontiers Media S.A.Frontiers in Materials2296-80162022-05-01910.3389/fmats.2022.797226797226Linkage of Macro- and Microscale Modeling Tools for Additive Manufacturing of SteelsJulia Sjöström0Julia Sjöström1A. Durga2Greta Lindwall3Department of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm, SwedenVBN Components AB, Uppsala, SwedenDepartment of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm, SwedenDepartment of Materials Science and Engineering, KTH Royal Institute of Technology, Stockholm, SwedenAdditive manufacturing (AM) offers several benefits including the capability to produce unique microstructures, geometrical freedom allowing for material and energy savings, and easy production lines with fewer post-processing steps. However, AM processes are complex and phenomena occurring at different length and time scales need to be understood and controlled to avoid challenges with, for example, defects, residual stresses, distortions, and alloy restrictions. To overcome some of these challenges and to have more control over the final product, computational tools for different length scales need to be combined. In this work, an 18Ni300 maraging steel part is studied to understand the link between the process parameters and the as-built microstructure. The temperature evolution during laser powder bed fusion is simulated using the MSC simulation software Simufact Additive. This result is then linked to microscale models within the Thermo-Calc software package to predict the elemental micro-segregation, martensite start (Ms) temperature, and martensite fraction. The different values of the key process parameters such as laser speed, laser power, heating efficiency, and baseplate temperature are considered, leading to different thermal histories. The thermal histories affect the elemental segregation across the solidification structure, which in turn results in different Ms temperatures at different locations of the built part. It is found that higher laser energy generally causes higher temperatures and higher cooling rates, which results in a larger degree of elemental segregation and lower Ms temperatures in segregated regions. Furthermore, the segregated regions are predicted to have Ms temperatures below 200°C, which would result in retained austenite when using a baseplate temperature of 200°C. On the other hand, by using a baseplate temperature of 100°C, all regions would reach temperatures below the Ms temperature, and an almost fully martensitic structure would be possible. In summary, it is demonstrated how the linkage of macro- and microscale modeling tools for AM can be used to optimize the process and produce the desired microstructure, thereby achieving the desired mechanical properties.https://www.frontiersin.org/articles/10.3389/fmats.2022.797226/fullmaraging steellaser powder bed fusiontemperature evolutionmacro-scale modelingmicro-segregationmulti-scale modeling
spellingShingle Julia Sjöström
Julia Sjöström
A. Durga
Greta Lindwall
Linkage of Macro- and Microscale Modeling Tools for Additive Manufacturing of Steels
Frontiers in Materials
maraging steel
laser powder bed fusion
temperature evolution
macro-scale modeling
micro-segregation
multi-scale modeling
title Linkage of Macro- and Microscale Modeling Tools for Additive Manufacturing of Steels
title_full Linkage of Macro- and Microscale Modeling Tools for Additive Manufacturing of Steels
title_fullStr Linkage of Macro- and Microscale Modeling Tools for Additive Manufacturing of Steels
title_full_unstemmed Linkage of Macro- and Microscale Modeling Tools for Additive Manufacturing of Steels
title_short Linkage of Macro- and Microscale Modeling Tools for Additive Manufacturing of Steels
title_sort linkage of macro and microscale modeling tools for additive manufacturing of steels
topic maraging steel
laser powder bed fusion
temperature evolution
macro-scale modeling
micro-segregation
multi-scale modeling
url https://www.frontiersin.org/articles/10.3389/fmats.2022.797226/full
work_keys_str_mv AT juliasjostrom linkageofmacroandmicroscalemodelingtoolsforadditivemanufacturingofsteels
AT juliasjostrom linkageofmacroandmicroscalemodelingtoolsforadditivemanufacturingofsteels
AT adurga linkageofmacroandmicroscalemodelingtoolsforadditivemanufacturingofsteels
AT gretalindwall linkageofmacroandmicroscalemodelingtoolsforadditivemanufacturingofsteels