Understanding Melt Pool Behavior of 316L Stainless Steel in Laser Powder Bed Fusion Additive Manufacturing

In the laser powder bed fusion additive manufacturing process, the quality of fabrications is intricately tied to the laser–matter interaction, specifically the formation of the melt pool. This study experimentally examined the intricacies of melt pool characteristics and surface topography across d...

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Main Authors: Zilong Zhang, Tianyu Zhang, Can Sun, Sivaji Karna, Lang Yuan
Format: Article
Language:English
Published: MDPI AG 2024-01-01
Series:Micromachines
Subjects:
Online Access:https://www.mdpi.com/2072-666X/15/2/170
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author Zilong Zhang
Tianyu Zhang
Can Sun
Sivaji Karna
Lang Yuan
author_facet Zilong Zhang
Tianyu Zhang
Can Sun
Sivaji Karna
Lang Yuan
author_sort Zilong Zhang
collection DOAJ
description In the laser powder bed fusion additive manufacturing process, the quality of fabrications is intricately tied to the laser–matter interaction, specifically the formation of the melt pool. This study experimentally examined the intricacies of melt pool characteristics and surface topography across diverse laser powers and speeds via single-track laser scanning on a bare plate and powder bed for 316L stainless steel. The results reveal that the presence of a powder layer amplifies melt pool instability and worsens irregularities due to increased laser absorption and the introduction of uneven mass from the powder. To provide a comprehensive understanding of melt pool dynamics, a high-fidelity computational model encompassing fluid dynamics, heat transfer, vaporization, and solidification was developed. It was validated against the measured melt pool dimensions and morphology, effectively predicting conduction and keyholing modes with irregular surface features. Particularly, the model explained the forming mechanisms of a defective morphology, termed swell-undercut, at high power and speed conditions, detailing the roles of recoil pressure and liquid refilling. As an application, multiple-track simulations replicate the surface features on cubic samples under two distinct process conditions, showcasing the potential of the laser–matter interaction model for process optimization.
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spelling doaj.art-7d192ea33cb34021b77fd1b61526dc5b2024-02-23T15:27:30ZengMDPI AGMicromachines2072-666X2024-01-0115217010.3390/mi15020170Understanding Melt Pool Behavior of 316L Stainless Steel in Laser Powder Bed Fusion Additive ManufacturingZilong Zhang0Tianyu Zhang1Can Sun2Sivaji Karna3Lang Yuan4Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29201, USADepartment of Mechanical Engineering, University of South Carolina, Columbia, SC 29201, USADepartment of Mechanical Engineering, University of South Carolina, Columbia, SC 29201, USADepartment of Mechanical Engineering, University of South Carolina, Columbia, SC 29201, USADepartment of Mechanical Engineering, University of South Carolina, Columbia, SC 29201, USAIn the laser powder bed fusion additive manufacturing process, the quality of fabrications is intricately tied to the laser–matter interaction, specifically the formation of the melt pool. This study experimentally examined the intricacies of melt pool characteristics and surface topography across diverse laser powers and speeds via single-track laser scanning on a bare plate and powder bed for 316L stainless steel. The results reveal that the presence of a powder layer amplifies melt pool instability and worsens irregularities due to increased laser absorption and the introduction of uneven mass from the powder. To provide a comprehensive understanding of melt pool dynamics, a high-fidelity computational model encompassing fluid dynamics, heat transfer, vaporization, and solidification was developed. It was validated against the measured melt pool dimensions and morphology, effectively predicting conduction and keyholing modes with irregular surface features. Particularly, the model explained the forming mechanisms of a defective morphology, termed swell-undercut, at high power and speed conditions, detailing the roles of recoil pressure and liquid refilling. As an application, multiple-track simulations replicate the surface features on cubic samples under two distinct process conditions, showcasing the potential of the laser–matter interaction model for process optimization.https://www.mdpi.com/2072-666X/15/2/170additive manufacturinglaser powder bed fusionfluid dynamicsmelt pool instabilitysurface topography
spellingShingle Zilong Zhang
Tianyu Zhang
Can Sun
Sivaji Karna
Lang Yuan
Understanding Melt Pool Behavior of 316L Stainless Steel in Laser Powder Bed Fusion Additive Manufacturing
Micromachines
additive manufacturing
laser powder bed fusion
fluid dynamics
melt pool instability
surface topography
title Understanding Melt Pool Behavior of 316L Stainless Steel in Laser Powder Bed Fusion Additive Manufacturing
title_full Understanding Melt Pool Behavior of 316L Stainless Steel in Laser Powder Bed Fusion Additive Manufacturing
title_fullStr Understanding Melt Pool Behavior of 316L Stainless Steel in Laser Powder Bed Fusion Additive Manufacturing
title_full_unstemmed Understanding Melt Pool Behavior of 316L Stainless Steel in Laser Powder Bed Fusion Additive Manufacturing
title_short Understanding Melt Pool Behavior of 316L Stainless Steel in Laser Powder Bed Fusion Additive Manufacturing
title_sort understanding melt pool behavior of 316l stainless steel in laser powder bed fusion additive manufacturing
topic additive manufacturing
laser powder bed fusion
fluid dynamics
melt pool instability
surface topography
url https://www.mdpi.com/2072-666X/15/2/170
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