Processing of Haynes® 282® Alloy by Laser Powder Bed Fusion Technology

Abstract The proposed work investigates the hybrid surface characterisation of intra thin-walled Ti6Al4V surfaces fabricated using laser powder bed fusion technology. The thin-walled samples were characterised using scanning electron microscopy and Opto-digital microscopy techniques. The fractal dimensional analysis was performed using ImageJ software integrated with an open-source MultiFrac plug-in. The surface microscopy analysis revealed satellites powder particles, partially melted powder particles, spherical balling, and pores on the thin-walled surface. The fractal dimension establishes a correlation between the surface roughness values. The surface areal surface parameters analysis suggested variation along the build direction of thin-walled Ti6Al4V sample. The development of sharp peaks and thus higher Ra, Sku and Ssk values were found along the build direction of the intra thin-walled samples. Therefore, the combination of areal surface topography analysis and fractal dimension approach can be a promising methodology towards surface characterisation of additively manufactured complex thin-walled surfaces.

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Structural investigations of Fe-Zr-Si-Cu metallic glass with low glass-forming ability produced in Laser Powder Bed Fusion technology

Materials & Design ◽

10.1016/j.matdes.2021.110112 ◽

2021 ◽

pp. 110112

Author(s):

Łukasz Szczepański ◽

Markus Bambach ◽

Felix Jensch ◽

Andrzej Ambroziak ◽

Tomasz Kurzynowski

Keyword(s):

Metallic Glass ◽

Glass Forming Ability ◽

Powder Bed Fusion ◽

Fusion Technology ◽

Laser Powder Bed Fusion ◽

Structural Investigations ◽

Powder Bed ◽

Glass Forming

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Numerical investigation into cleanability of support structures produced by powder bed fusion technology

Rapid Prototyping Journal ◽

10.1108/rpj-02-2021-0039 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Giampaolo Campana ◽

Eckart Uhlmann ◽

Mattia Mele ◽

Luca Raffaelli ◽

André Bergmann ◽

...

Keyword(s):

Fluid Dynamics ◽

Preliminary Investigation ◽

Design Guidelines ◽

Powder Bed Fusion ◽

Support Structures ◽

Fusion Technology ◽

Laser Powder Bed Fusion ◽

Content Type ◽

Powder Bed ◽

New Guidelines

Purpose Support structures used in laser powder bed fusion are often difficult to clean from unsintered powder at the end of the process. This issue can be significantly reduced through a proper design of these auxiliary structures. This paper aims to investigate preliminary the airflow within differently oriented support structures and to provide design guidelines to enhance their cleanability, especially the depowdering of them. Design/methodology/approach This study investigates the cleanability of support structures in powder bed fusion technology. Digital models of cleaning operations were designed through computer-aided engineering systems. Simulations of the airflow running into the powder entrapped within the thin walls of auxiliary supports were implemented by computational fluid dynamics. This approach was applied to a set of randomly generated geometrical configurations to determine the air turbulence intensity depending on their design. Findings The results, which are based on the assumption that a relationship exists between turbulence and powder removal effectiveness, demonstrated that the maximum cleanability is obtainable through specific relative rotations between consecutive support structures. Furthermore, it was possible to highlight the considerable influence of the auxiliary structures next to the fluid inlet. These relevant findings establish optimal design rules for the cleanability of parts manufactured by powder bed fusion processes. Originality/value This study presents a preliminary investigation into the cleanability of support structures in laser powder bed fusion, which has not been addressed by previous literature. The results allow for a better understanding of the fluid dynamics during cleaning operations. New guidelines to enhance the cleanability of support structures are provided based on the results of simulations.

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Near-Threshold Fatigue Crack Growth Rates of Laser Powder Bed Fusion Produced Ti-6Al-4V

SSRN Electronic Journal ◽

10.2139/ssrn.3622627 ◽

2020 ◽

Author(s):

Thorsten Hermann Becker ◽

Nur Mohamed Dhansay ◽

Gerrit Matthys Ter Haar ◽

Kim Vanmeensel

Keyword(s):

Fatigue Crack ◽

Fatigue Crack Growth ◽

Crack Growth ◽

Growth Rates ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Crack Growth Rates ◽

Near Threshold

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Machine-Learning Assisted Laser Powder Bed Fusion Process Optimization for AlSi10mg: New Microstructure Description Indices and Fracture Mechanisms

SSRN Electronic Journal ◽

10.2139/ssrn.3681162 ◽

2020 ◽

Author(s):

Qian Liu ◽

Hongkun Wu ◽

Moses J. Paul ◽

Peidong He ◽

Zhongxiao Peng ◽

...

Keyword(s):

Machine Learning ◽

Process Optimization ◽

Fusion Process ◽

Fracture Mechanisms ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Powder Bed

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On the Relevance of Volumetric Energy Density in the Investigation of Inconel 718 Laser Powder Bed Fusion

Materials ◽

10.3390/ma13030538 ◽

2020 ◽

Vol 13 (3) ◽

pp. 538 ◽

Cited By ~ 6

Author(s):

Fabrizia Caiazzo ◽

Vittorio Alfieri ◽

Giuseppe Casalino

Keyword(s):

Surface Roughness ◽

Energy Density ◽

Process Parameters ◽

Vickers Hardness ◽

Powder Bed Fusion ◽

Processing Conditions ◽

Laser Powder Bed Fusion ◽

Powder Bed ◽

Fractional Density ◽

Experimental Variation

Laser powder bed fusion (LPBF) can fabricate products with tailored mechanical and surface properties. In fact, surface texture, roughness, pore size, the resulting fractional density, and microhardness highly depend on the processing conditions, which are very difficult to deal with. Therefore, this paper aims at investigating the relevance of the volumetric energy density (VED) that is a concise index of some governing factors with a potential operational use. This paper proves the fact that the observed experimental variation in the surface roughness, number and size of pores, the fractional density, and Vickers hardness can be explained in terms of VED that can help the investigator in dealing with several process parameters at once.

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