Benchmark test artifacts for selective laser melting – a critical review

Background: Selective laser melting is the best-established additive manufacturing technology for high-quality metal part manufacturing. However, the widespread acceptance of the technology is still underachieved, especially in critical applications, due to the absence of a thorough understanding of the technology, although several benchmark test artifacts have been developed to characterize the performance of selective laser melting machines. Objective: The objective of this paper is to inspire new designs of benchmark test artifacts to understand the selective laser melting process better and promote the acceptance of the selective laser melting technology. Method: The existing benchmark test artifacts for selective laser melting are analyzed comparatively, and the design guidelines are discussed. Results: The modular approach should still be adopted in designing new benchmark test artifacts in the future, and task-specific test artifacts may also need to be considered further to validate the machine performance for critical applications. The inclusion of the design model in the manufactured artifact, instead of the conformance to the design specifications, should be evaluated after the artifact is measured for the applications requiring high-dimensional accuracy and high surface quality. Conclusion: The benchmark test artifact for selective laser melting is still under development, and a breakthrough of the measuring technology for internal and/or inaccessible features will be beneficial for understanding the technology.

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Fabrication of Mesh Patterns Using a Selective Laser-Melting Process

Applied Sciences ◽

10.3390/app9091922 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1922 ◽

Cited By ~ 3

Author(s):

Tae Woo Hwang ◽

Young Yun Woo ◽

Sang Wook Han ◽

Young Hoon Moon

Keyword(s):

Selective Laser Melting ◽

Laser Scanning ◽

Dimensional Accuracy ◽

Base Plate ◽

Steel Powder ◽

Melting Process ◽

304 Stainless Steel ◽

Process Conditions ◽

Laser Melting ◽

Metal Mesh

The selective laser-melting (SLM) process can be applied to the additive building of complex metal parts using melting metal powder with laser scanning. A metal mesh is a common type of metal screen consisting of parallel rows and intersecting columns. It is widely used in the agricultural, industrial, transportation, and machine protection sectors. This study investigated the fabrication of parts containing a mesh pattern from the SLM of AISI 304 stainless steel powder. The formation of a mesh pattern has a strong potential to increase the functionality and cost-effectiveness of the SLM process. To fabricate a single-layered thin mesh pattern, laser layering has been conducted on a copper base plate. The high thermal conductivity of copper allows heat to pass through it quickly, and prevents the adhesion of a thin laser-melted layer. The effects of the process conditions such as the laser scan speed and scanning path on the size and dimensional accuracy of the fabricated mesh patterns were characterized. As the analysis results indicate, a part with a mesh pattern was successfully obtained, and the application of the proposed method was shown to be feasible with a high degree of reliability.

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Selective Laser Melting Process of Al–Based Pyramidal Horns for the W-Band: Fabrication and Testing

Journal of Infrared Millimeter and Terahertz Waves ◽

10.1007/s10762-020-00759-2 ◽

2021 ◽

Author(s):

L. Lamagna ◽

A. Paiella ◽

S. Masi ◽

L. Bottini ◽

A. Boschetto ◽

...

Keyword(s):

Selective Laser Melting ◽

High Surface ◽

Melting Process ◽

Horn Antenna ◽

Post Processing ◽

Laser Melting ◽

Performance Impact ◽

Horn Antennas ◽

Sand Blasting ◽

W Band

AbstractIn the context of exploring the possibility of using Al-powder Selective Laser Melting to fabricate horn antennas for astronomical applications at millimeter wavelengths, we describe the design, the fabrication, the mechanical characterization, and the electromagnetic performance of additive manufactured horn antennas for the W-band. Our aim, in particular, is to evaluate the performance impact of two basic kinds of surface post-processing (manual grinding and sand-blasting) to deal with the well-known issue of high surface roughness in 3D printed devices. We performed comparative tests of co-polar and cross-polar angular response across the whole W-band, assuming a commercially available rectangular horn antenna as a reference. Based on gain and directivity measurements of the manufactured samples, we find decibel-level detectable deviations from the behavior of the reference horn antenna, and marginal evidence of performance degradation at the top edge of the W-band. We conclude that both kinds of post-processing allow achieving good performance for the W-band, but the higher reliability and uniformity of the sand-blasting post-process encourage exploring similar techniques for further development of aluminum devices at these frequencies.

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In Implementing a Metal 3D AM Machine

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.786.356 ◽

2018 ◽

Vol 786 ◽

pp. 356-363

Author(s):

Tero Jokelainen ◽

Kimmo Mäkelä ◽

Aappo Mustakangas ◽

Jari Mäkelä ◽

Kari Mäntyjärvi

Keyword(s):

Additive Manufacturing ◽

Selective Laser Melting ◽

Dimensional Accuracy ◽

Acceptance Test ◽

Aisi 316L ◽

Laser Melting ◽

Geometrical Accuracy ◽

Machine Performance ◽

Geometrical Features ◽

Made In

Additive Manufacturing (AM) does not yet have a standardized way to measure performance. Here a AM machines dimensional accuracy is measured trough acceptance test (AT) and AM machines capability is tested trough test parts. Test parts are created with specific geometrical features using a 3D AM machine. Performance of the machine is then evaluated trough accuracy of test parts geometry. AM machine here uses selective laser melting (SLM) process. This machine has done Factory acceptance test (FAT) to ascertain this machine ́s geometrical accuracy with material AISI 316L. Manufacturer promises accuracy of ±0.05 mm. These parts are used as comparison to AT parts made in this study. After installation two AT parts are manufactured with AM machine. One with AISI 316L and one AlSi10Mg. Dimensional accuracy of geometrical features on these parts are then compared to FAT part and to one another. Machines capability is measured trough two test parts done with material AlSi10Mg. Two of the test parts are done at the same time using same model as the FAT. Parts are printed without supports and with features facing same directions. Features of these parts were then evaluated. Another test to find out AM machines capability was to create part consisting of pipes doing 90˚ angle resulting in horizontal and vertical holes. Dimensional accuracy and circularity of holes was measured. Through these tests machines capability is benchmarked.

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Experimental evaluation of selective laser melting process for optimized lattice structures

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408918803194 ◽

2018 ◽

Vol 233 (4) ◽

pp. 763-775 ◽

Cited By ~ 1

Author(s):

G De Pasquale ◽

F Luceri ◽

M Riccio

Keyword(s):

Selective Laser Melting ◽

Statistical Approach ◽

Dimensional Accuracy ◽

Melting Process ◽

Lattice Structures ◽

Metal Powders ◽

Laser Melting ◽

Material Density ◽

Volume Energy ◽

Appreciable Reduction

Lattice structures fabricated with micromelting of metal powders are promising solutions for lightweight applications. Additive manufacturing processes as selective laser melting are largely used to build bulk components, but the influence of laser settings on lattice struts morphology is not jet fully investigated. Previous studies demonstrate the effect of laser speed and layers thickness on the material density and lattice struts dimensions. In this paper, the effects of the laser volume energy density associated with the process setup parameters are analyzed in relation to the dimensional accuracy of lattice struts. The statistical approach based on design of experiments used in this paper allows getting appreciable reduction of the average errors of struts dimensions (from 48% to 16% and from 22% to 7% in horizontal and vertical orientations, respectively).

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Effect of Selective Laser Melting Process Parameters on the Quality of Al Alloy Parts: Powder Characterization, Density, Surface Roughness, and Dimensional Accuracy

Materials ◽

10.3390/ma11122343 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2343 ◽

Cited By ~ 43

Author(s):

Ahmed Maamoun ◽

Yi Xue ◽

Mohamed Elbestawi ◽

Stephen Veldhuis

Keyword(s):

Surface Roughness ◽

Selective Laser Melting ◽

Process Parameters ◽

Dimensional Accuracy ◽

High Strength ◽

Melting Process ◽

Al Alloys ◽

Al Alloy ◽

Laser Melting

Additive manufacturing (AM) of high-strength Al alloys promises to enhance the performance of critical components related to various aerospace and automotive applications. The key advantage of AM is its ability to generate lightweight, robust, and complex shapes. However, the characteristics of the as-built parts may represent an obstacle to the satisfaction of the parts’ quality requirements. The current study investigates the influence of selective laser melting (SLM) process parameters on the quality of parts fabricated from different Al alloys. A design of experiment (DOE) was used to analyze relative density, porosity, surface roughness, and dimensional accuracy according to the interaction effect between the SLM process parameters. The results show a range of energy densities and SLM process parameters for AlSi10Mg and Al6061 alloys needed to achieve “optimum” values for each performance characteristic. A process map was developed for each material by combining the optimized range of SLM process parameters for each characteristic to ensure good quality of the as-built parts. This study is also aimed at reducing the amount of post-processing needed according to the optimal processing window detected.

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Dimensional Accuracy Study of Open Cellular Structure CoCrMo Alloy Fabricated by Selective Laser Melting Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1133.280 ◽

2016 ◽

Vol 1133 ◽

pp. 280-284 ◽

Cited By ~ 9

Author(s):

Zahrul Adnan Mat Taib ◽

Wan Sharuzi Wan Harun ◽

Saiful Anwar Che Ghani ◽

Mohd Fadzil Faisae Ab Rashid ◽

Mohd Asnawi Omar ◽

...

Keyword(s):

Surface Area ◽

Selective Laser Melting ◽

Dimensional Accuracy ◽

Melting Process ◽

Laser Melting ◽

Cocrmo Alloy ◽

Orthodontic Implants ◽

Accuracy Study ◽

Manufacturing Techniques ◽

Metal Additive

Designing orthodontic implants with desired physical and biological performances and to fabricate net shape with complex anatomical shapes is still a challenge. Cautious design approaches followed by systematic manufacturing techniques that can achieve balanced physical performance in mono block implants mechanics is necessary to accomplish this objective. Metal additive manufacturing (MAM) technique such as selective laser melting (SLM) process is progressively being utilized for new biomaterials such as cobalt-chrome-molybdenum (CoCrMo). This study was designed to determine a dimensional accuracy of open cellular structures CoCrMo samples with designing volume based porosity ranging between 0 % (full dense) to 80 %. A maximum 2.10 % shrinkage was obtained by 80 % designed porosity sample. Samples with higher volume-to-surface area (full dense) demonstrated the low total amount of shrinkage as compared to lower volume-to-surface area (80 % designed porosity).

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Improving surface quality in selective laser melting based tool making

Journal of Intelligent Manufacturing ◽

10.1007/s10845-021-01744-9 ◽

2021 ◽

Author(s):

Filippo Simoni ◽

Andrea Huxol ◽

Franz-Josef Villmer

Keyword(s):

Surface Roughness ◽

Additive Manufacturing ◽

Surface Quality ◽

Selective Laser Melting ◽

Melting Process ◽

Laser Remelting ◽

Laser Melting ◽

Great Cost ◽

Starting Point ◽

Processing Techniques

AbstractIn the last years, Additive Manufacturing, thanks to its capability of continuous improvements in performance and cost-efficiency, was able to partly replace and redefine well-established manufacturing processes. This research is based on the idea to achieve great cost and operational benefits especially in the field of tool making for injection molding by combining traditional and additive manufacturing in one process chain. Special attention is given to the surface quality in terms of surface roughness and its optimization directly in the Selective Laser Melting process. This article presents the possibility for a remelting process of the SLM parts as a way to optimize the surfaces of the produced parts. The influence of laser remelting on the surface roughness of the parts is analyzed while varying machine parameters like laser power and scan settings. Laser remelting with optimized parameter settings considerably improves the surface quality of SLM parts and is a great starting point for further post-processing techniques, which require a low initial value of surface roughness.

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