| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Reijonen, Joni
VTT Technical Research Centre of Finland
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (14/14 displayed)
- 2024Effect of laser focal point position on porosity and melt pool geometry in laser powder bed fusion additive manufacturingcitations
- 2022High-coercivity NdFeB Printed Magnets With Laser Powder Bed Fusion Method
- 2022Single-Track Laser Scanning as a Method for Evaluating Printability: The Effect of Substrate Heat Treatment on Melt Pool Geometry and Cracking in Medium Carbon Tool Steelcitations
- 2022Laser Powder Bed Fusion Of High Carbon Tool Steels
- 2022Experimental and Calphad Methods for Evaluating Residual Stresses and Solid-State Shrinkage after Solidificationcitations
- 2022Opportunities Of Physics-Based Multi-Scale Modeling Tools In Assessing Intra-Grain Heterogeneities, Polycrystal Properties And Residual Stresses Of AM Metals
- 2021Micromechanical modeling approach to single track deformation, phase transformation and residual stress evolution during selective laser melting using crystal plasticitycitations
- 2021Cross-testing laser powder bed fusion production machines and powders: Variability in mechanical properties of heat-treated 316L stainless steelcitations
- 2021Cross-testing laser powder bed fusion production machines and powderscitations
- 2021Cross-testing laser powder bed fusion production machines and powders:Variability in mechanical properties of heat-treated 316L stainless steelcitations
- 2021Method for embedding components during additive manufacturing of metal parts
- 2020On the effect of shielding gas flow on porosity and melt pool geometry in laser powder bed fusion additive manufacturingcitations
- 2017Feasibility of selective laser melting process in manufacturing of digital spare parts
- 2017Circular Economy Concept In Additive Manufacturing
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article
Effect of laser focal point position on porosity and melt pool geometry in laser powder bed fusion additive manufacturing
Abstract
In laser powder bed fusion (PBF-LB) additive manufacturing (AM), the laser beam is the fundamental tool used to selectively melt metal powder layer-upon-layer to form a 3-dimensional part. Studies on the effect of the laser scanning parameters (power, speed, hatch distance, and scanning strategy in general) on part quality are abundant; however, far less emphasis has been given to the effect of the laser beam and how it is focused on the laser-material interaction plane. Here, we have studied the effect of laser beam focal point position on porosity and melt pool geometry in PBF-LB AM. In addition, we also study how the various energy density parameters developed for laser melting processes correlate with melt pool dimensions in a situation where the laser beam focal point position (and the beam diameter and laser intensity change at work plane caused by it), is taken into consideration. Furthermore, we assess the possibility of using co-axial, photodiode-based melt pool monitoring signals as a means to monitor the thermal emissions of the process, and how it correlates with the resulting melt pool geometry. It was found that melt pool penetration experiences a major decrease when the focal point position is shifted by more than ±1 mm (or 30% of Rayleigh length), which could be considered as a tolerance limit for acceptable focus shift in PBF-LB machines. Focus shifts larger than this were effectively captured by the photodiode signals, indicating the potential of using such photodiode-based melt pool monitoring systems for continuous monitoring of focus shift in PBF-LB AM. Finally, it was shown that all the studied energy density parameters, except volumetric energy density, were able to capture the trend in normalized melt pool dimensions when focus position is introduced as a variable. A new energy density metric by normalizing the melt pool monitoring signal intensity with the beam area was introduced and shown to correlate with the normalized melt pool dimensions.