Visualization of the process of selective laser melting

This paper deals with the visualization of the previously simulated by the authors selective laser melting process in order to simplify the analysis of the results and the selection of technological parameters of the additive production unit. The article presents two possible approaches for visualization of the selective laser fusion process and supported functions which simplify the work and research in the framework of the new technology. The implemented approaches will reduce the requirements for the level of training of specialists working on Russian-made equipment. In the two-dimensional visualization mode, the emphasis is on the possibility of a more detailed study of the process. In a three-dimensional there is the ability of the broader scope and to see the big picture. Several implemented principles of geometry simplification for visual representation are considered. The advantages and disadvantages of the work done and the results obtained are presented.

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Microstructure Characterization of AlSi10Mg Fabricated by Selective Laser Melting Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.941.1437 ◽

2018 ◽

Vol 941 ◽

pp. 1437-1442

Author(s):

Takashi Maeshima ◽

Keiichiro Oh-Ishi ◽

Hiroaki Kadoura ◽

Masashi Hara

Keyword(s):

Selective Laser Melting ◽

Molten Pool ◽

Three Dimensional ◽

Melting Process ◽

Powder Layer ◽

Base Temperature ◽

Fish Scale ◽

Laser Melting ◽

Microstructure Observation ◽

Three Dimensional Finite Element

Multi-scale microstructure observation and three dimensional finite element thermal analysis of AlSi10Mg alloy fabricated by selective laser melting (SLM) process were demonstrated in order to understand the microstructure formation process during SLM fabrication. The unique hierarchically microstructures were observed: (1) the “fish scale” microstructure corresponding to a part of molten pool consists of columnar and equiaxed grains and (2) these grains contain a substructure of α-Al surrounded by Si particles. It is revealed that a supersaturated Si concentration due to the predicted rapid cooling rate on the order of 106 oC/s. In addition, the base temperature during the fabrication increases gradually with some peak temperature of each laser path as the laser scan has proceeded on a powder layer. Although the thermal changes cause no melting of the AlSi10Mg except directly fused region by selective laser so called molten pool, those are capable of causing precipitation and/or clustering.

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Fabrication of Cu-Al-Ni Shape Memory Alloy by Selective Laser Melting Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.941.1570 ◽

2018 ◽

Vol 941 ◽

pp. 1570-1573

Author(s):

Ken Imai ◽

Toshi Taka Ikeshoji ◽

Kazuya Nakamura ◽

Motonori Nishida ◽

Yuji Sugitani ◽

...

Keyword(s):

Shape Memory ◽

Selective Laser Melting ◽

Elastic Anisotropy ◽

Copper Alloys ◽

Three Dimensional ◽

Melting Process ◽

Laser Melting ◽

Good Shape ◽

Ni Alloy ◽

Scan Speed

Additive manufacturing (AM) is a prominent technology in the industrial fields such as aerospace, medical, automotive and so on. Especially, selective laser melting (SLM) process is available to create three-dimensional complicated structures of various alloys such as stainless steel, titanium alloy, aluminium alloy, nickel-based superalloy and so on. And also, copper and copper alloys are used as a material for products with complicated shape, electrical components, and a heat exchanger because of having the high electrical conductivity and the high thermal conductivity. It is known that copper alloys show a good shape memory behaviour by adding Al, Ni and Zn. Especially, Cu-Al-Ni alloy shows a good shape memory properties at high temperature. However, it is difficult to fabricate high-density Cu-Al-Ni alloy by the SLM process. This is mainly because Cu-Al-Ni alloy has high elastic anisotropy and brittleness in polycrystalline state. In this research, the optimum fabrication condition of Cu-Al-Ni alloy by SLM process was investigated. The optimum laser power and scan speed were able to be found by evaluating the surface morphology, density and microstructure of the as-build specimens.The maximum density of the as-built specimen was 99.47%.

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Three-Dimensional Temperature Gradient Mechanism in Selective Laser Melting of Ti-6Al-4V

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4028539 ◽

2014 ◽

Vol 136 (6) ◽

Cited By ~ 75

Author(s):

C. H. Fu ◽

Y. B. Guo

Keyword(s):

Temperature Gradient ◽

Selective Laser Melting ◽

Molten Pool ◽

Three Dimensional ◽

Melting Process ◽

Layer By Layer ◽

Laser Melting ◽

Transient Nature ◽

Melting Pool ◽

Three Dimensional Finite Element

Selective laser melting (SLM) is widely used in making three-dimensional functional parts layer by layer. Temperature magnitude and history during SLM directly determine the molten pool dimensions and surface integrity. However, due to the transient nature and small size of the molten pool, the temperature gradient and the molten pool size are challenging to measure and control. A three-dimensional finite element (FE) simulation model has been developed to simulate multilayer deposition of Ti-6Al-4 V in SLM. A physics-based layer buildup approach coupled with a surface moving heat flux was incorporated into the modeling process. The melting pool shape and dimensions were predicted and experimentally validated. Temperature gradient and thermal history in the multilayer buildup process was also obtained. Furthermore, the influences of process parameters and materials on the melting process were evaluated.

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Three-dimensional numerical simulation of selective laser melting process based on SPH method

Journal of Manufacturing Processes ◽

10.1016/j.jmapro.2021.09.018 ◽

2021 ◽

Vol 71 ◽

pp. 224-236

Author(s):

Yunji Qiu ◽

Xiaofeng Niu ◽

Tingting Song ◽

Mengqing Shen ◽

Wenqi Li ◽

...

Keyword(s):

Numerical Simulation ◽

Selective Laser Melting ◽

Three Dimensional ◽

Melting Process ◽

Laser Melting ◽

Sph Method ◽

Selective Laser Melting Process

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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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Experimental and numerical investigation on lattice structures fabricated by selective laser melting process under quasi-static and dynamic loadings

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-020-06112-0 ◽

2021 ◽

Author(s):

Reza Saremian ◽

Mohsen Badrossamay ◽

Ehsan Foroozmehr ◽

Mahmoud Kadkhodaei ◽

Foroozan Forooghi

Keyword(s):

Numerical Investigation ◽

Selective Laser Melting ◽

Melting Process ◽

Lattice Structures ◽

Laser Melting ◽

Selective Laser Melting Process ◽

Dynamic Loadings

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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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3DP Printing of Oral Solid Formulations: A Systematic Review

Pharmaceutics ◽

10.3390/pharmaceutics13030358 ◽

2021 ◽

Vol 13 (3) ◽

pp. 358 ◽

Cited By ~ 1

Author(s):

Chiara R. M. Brambilla ◽

Ogochukwu Lilian Okafor-Muo ◽

Hany Hassanin ◽

Amr ElShaer

Keyword(s):

Systematic Review ◽

Data Extraction ◽

New Technology ◽

Three Dimensional ◽

Extraction Process ◽

Carcinogenic Risk ◽

Drug Dissolution ◽

Dissolution Profile ◽

Disintegration Time ◽

Advantages And Disadvantages

Three-dimensional (3D) printing is a recent technology, which gives the possibility to manufacture personalised dosage forms and it has a broad range of applications. One of the most developed, it is the manufacture of oral solid dosage and the four 3DP techniques which have been more used for their manufacture are FDM, inkjet 3DP, SLA and SLS. This systematic review is carried out to statistically analyze the current 3DP techniques employed in manufacturing oral solid formulations and assess the recent trends of this new technology. The work has been organised into four steps, (1) screening of the articles, definition of the inclusion and exclusion criteria and classification of the articles in the two main groups (included/excluded); (2) quantification and characterisation of the included articles; (3) evaluation of the validity of data and data extraction process; (4) data analysis, discussion, and conclusion to define which technique offers the best properties to be applied in the manufacture of oral solid formulations. It has been observed that with SLS 3DP technique, all the characterisation tests required by the BP (drug content, drug dissolution profile, hardness, friability, disintegration time and uniformity of weight) have been performed in the majority of articles, except for the friability test. However, it is not possible to define which of the four 3DP techniques is the most suitable for the manufacture of oral solid formulations, because the selection is affected by different parameters, such as the type of formulation, the physical-mechanical properties to achieve. Moreover, each technique has its specific advantages and disadvantages, such as for FDM the biggest challenge is the degradation of the drug, due to high printing temperature process or for SLA is the toxicity of the carcinogenic risk of the photopolymerising material.

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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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