Laser-Based Additive Manufacturing of Metals

2011 ◽  
Vol 227 ◽  
pp. 92-95 ◽  
Author(s):  
Sanjay Kumar ◽  
Sisa Pityana
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Laser Melting ◽  
Laser Engineered Net Shaping ◽  
Laminated Object Manufacturing ◽  
Key Issues ◽  
Net Shaping ◽  
Am Processes

For making metallic products through Additive Manufacturing (AM) processes, laser-based systems play very significant roles. Laser-based processes such as Selective Laser Melting (SLM) and Laser Engineered Net Shaping (LENS) are dominating processes while Laminated Object Manufacturing (LOM) has also been used. The paper will highlight key issues without going into details and try to present comparative pictures of the aforementioned processes. The issues included are machine, materials, applications, comparison, various possibilities and future works.

scholarly journals An Overview of Additive Manufacturing Technologies—A Review to Technical Synthesis in Numerical Study of Selective Laser Melting

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3895 ◽  
Author(s):  
Abbas Razavykia ◽  
Eugenio Brusa ◽  
Cristiana Delprete ◽  
Reza Yavari
Keyword(s):  
Numerical Simulation ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Powder Bed Fusion ◽  
Laser Melting ◽  
Powder Bed ◽  
Part Quality ◽  
Melt Pool ◽  
Wide Range ◽  
Am Processes

Additive Manufacturing (AM) processes enable their deployment in broad applications from aerospace to art, design, and architecture. Part quality and performance are the main concerns during AM processes execution that the achievement of adequate characteristics can be guaranteed, considering a wide range of influencing factors, such as process parameters, material, environment, measurement, and operators training. Investigating the effects of not only the influential AM processes variables but also their interactions and coupled impacts are essential to process optimization which requires huge efforts to be made. Therefore, numerical simulation can be an effective tool that facilities the evaluation of the AM processes principles. Selective Laser Melting (SLM) is a widespread Powder Bed Fusion (PBF) AM process that due to its superior advantages, such as capability to print complex and highly customized components, which leads to an increasing attention paid by industries and academia. Temperature distribution and melt pool dynamics have paramount importance to be well simulated and correlated by part quality in terms of surface finish, induced residual stress and microstructure evolution during SLM. Summarizing numerical simulations of SLM in this survey is pointed out as one important research perspective as well as exploring the contribution of adopted approaches and practices. This review survey has been organized to give an overview of AM processes such as extrusion, photopolymerization, material jetting, laminated object manufacturing, and powder bed fusion. And in particular is targeted to discuss the conducted numerical simulation of SLM to illustrate a uniform picture of existing nonproprietary approaches to predict the heat transfer, melt pool behavior, microstructure and residual stresses analysis.

An Investigation of Process Parameters on Selective Laser Melting of Nitinol

2013 ◽  
Author(s):  
Jason Walker ◽  
Mohammad Elahinia ◽  
Christoph Haberland
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Material Behavior ◽  
Laser Melting ◽  
Direct Fabrication ◽  
Shape Memory Effects ◽  
Near Net Shaping ◽  
Net Shaping ◽  
Actuation Systems

Nitinol’s superelastic and shape memory effects can be used in passive or active actuation systems. Often used in the aerospace industry, the use of Nitinol for actuation is also growing in the biomedical fields and elsewhere. However, the industry currently lacks the ability to produce complex Nitinol actuators, which is strictly limiting its potential. The extreme difficulty of machining Nitinol complicates manufacturing processes. Furthermore, the transformation temperatures which drive Nitinol’s unique behavior are extremely sensitive to the relative concentrations of nickel and titanium. Therefore, exceptionally tight compositional control during production is necessary to guarantee ideal material behavior. Additive manufacturing (AM) is a near-net-shaping technology which allows for the direct fabrication of complex metallic components. In this way, the (lack of) machinability of Nitinol is no longer an issue because no traditional machining is required during fabrication. Using AM also enables production of 3D geometries that are not possible using traditional techniques. Features such as engineered porosity, hollow parts, curved holes and filigree structures are suddenly realizable. Furthermore, direct CAD fabrication reduces the timescale of the concept-to-prototype transition. A major breakthrough in additive manufacturing came with the development of fiber laser technology in the mid-1990’s, which enables direct melting of manufacturing grade metals into fully dense parts. This technology became known as selective laser melting (SLM). Despite its huge potential, SLM of Nitinol has received little attention from the engineering world. In the present work, two different SLM machines (Realzier SLM 100 and Phenix Systems PXM) are used to develop Nitinol components directly from powder. Adjustment and optimization of the process parameters on the product are analyzed and compared.

Laser Based Manufacturing of Ti6Al4V: A Comparison of LENS and Selective Laser Melting

2019 ◽  
Vol 950 ◽  
pp. 44-49
Author(s):  
Nana K.K. Arthur
Keyword(s):  
Selective Laser Melting ◽  
Manufacturing Systems ◽  
Tensile Elongation ◽  
Lamellar Microstructure ◽  
Lens System ◽  
Laser Melting ◽  
Laser Engineered Net Shaping ◽  
Test Geometry ◽  
Microstructural Evaluation ◽  
Net Shaping

The laser engineered net shaping (LENS) system was used for the laser based manufacturing of a test geometry used to assess the performance of additive manufacturing systems. This system was preferred over a selective laser melting (SLM) system due to certain inherent benefits that would promote the manufacture of the test geometry where the SLM system had failed due to part delamination. The test geometry was successfully manufactured on the LENS system and machined to produce test specimen for mechanical testing and microstructural evaluation. Investigations revealed that the α-β lamellar microstructure was formed via in situ martensitic decomposition of the α’ structure. This resulted in promising yield and tensile strengths in excess of 900 MPa and high tensile elongation up to 13%.

scholarly journals Improving surface quality in selective laser melting based tool making

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.

scholarly journals Directionally-Dependent Mechanical Properties of Ti6Al4V Manufactured by Electron Beam Melting (EBM) and Selective Laser Melting (SLM)

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3603
Author(s):  
Tim Pasang ◽  
Benny Tavlovich ◽  
Omry Yannay ◽  
Ben Jakson ◽  
Mike Fry ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Tensile Strength ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Electron Beam Melting ◽  
Rolling Direction ◽  
Laser Melting ◽  
Plate Rolling

An investigation of mechanical properties of Ti6Al4V produced by additive manufacturing (AM) in the as-printed condition have been conducted and compared with wrought alloys. The AM samples were built by Selective Laser Melting (SLM) and Electron Beam Melting (EBM) in 0°, 45° and 90°—relative to horizontal direction. Similarly, the wrought samples were also cut and tested in the same directions relative to the plate rolling direction. The microstructures of the samples were significantly different on all samples. α′ martensite was observed on the SLM, acicular α on EBM and combination of both on the wrought alloy. EBM samples had higher surface roughness (Ra) compared with both SLM and wrought alloy. SLM samples were comparatively harder than wrought alloy and EBM. Tensile strength of the wrought alloy was higher in all directions except for 45°, where SLM samples showed higher strength than both EBM and wrought alloy on that direction. The ductility of the wrought alloy was consistently higher than both SLM and EBM indicated by clear necking feature on the wrought alloy samples. Dimples were observed on all fracture surfaces.

Assessment of Heat Treatment Effect on AlSi10Mg by Selective Laser Melting through Indentation Testing

2019 ◽  
Vol 813 ◽  
pp. 171-177 ◽  
Author(s):  
Giacomo Maculotti ◽  
Gianfranco Genta ◽  
Massimo Lorusso ◽  
Maurizio Galetto
Keyword(s):  
Selective Laser Melting ◽  
Melt Spinning ◽  
Ad Hoc ◽  
Indentation Test ◽  
Al Alloy ◽  
Laser Melting ◽  
Heat Treated ◽  
Processing Properties ◽  
Am Processes ◽  
Metal Additive

Selective Laser Melting (SLM) is one of the leader metal Additive Manufacturing (AM) processes thanks to its capability of coupling freeform design and environmental and economical sustainability to high mechanical properties. AlSi10Mg is a light weight Al-alloy with interesting processing properties and enhanced strength thanks to the presence of Mg, which, hence, finds application in several industrial fields. Furthermore, SLM allows overcoming those design constraints set by casting and melt spinning; however, SLM AlSi10Mg components require to be heat treated, both to strengthen the material and to engineer the microstructure. In this work, in order to assess the effectiveness of heat treatments on AlSi10Mg by SLM, an ad hoc analysis procedure based on statistical tools is applied in combination with indentation characterisation tests. In particular, to achieve full scale characterisation, traditional Brinell hardness and Instrumented Indentation Test (IIT) in macro and nano-range are considered. In particular, IIT is applied both at the lower end of macro range to provide consistency and statistically investigate relationship with Brinell scale and in the nano-range, enabling local, i.e. grain, and surface properties to be characterised.

scholarly journals Selective Laser Melting of Crack-Free High Density M2 High Speed Steel Parts by Baseplate Preheating

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Karolien Kempen ◽  
Bey Vrancken ◽  
Sam Buls ◽  
Lore Thijs ◽  
Jan Van Humbeeck ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
High Speed ◽  
Crack Formation ◽  
High Speed Steel ◽  
Thermal Gradients ◽  
Laser Melting ◽  
Mechanical And Physical Properties ◽  
The World ◽  
M2 High Speed Steel

Cracks and delamination, resulting from residual stresses, are a barrier in the world of additive manufacturing and selective laser melting (SLM) that prohibits the use of many metals in this field. By preheating the baseplate, thermal gradients are lowered and stresses can be reduced. In this work, some initial tests were performed with M2 high speed steel (HSS). The influence of preheating on density and mechanical and physical properties is investigated. The paper shows many promising results for the production of SLM parts in materials that are very sensitive to crack formation and delamination. When using a preheating of 200 °C, crack-free M2 HSS parts were produced with a relative density of 99.8%.

Einbringen von Gewinden in SLM-Bauteile*/Insertion of threads into SLM components – Reliable strategy for inserting threads into additively manufactured components

2019 ◽  
Vol 109 (01-02) ◽  
pp. 24-29
Author(s):  
E. Abele ◽  
T. Scherer ◽  
F. Geßner ◽  
M. Weigold
Keyword(s):  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Downstream Processing ◽  
Manufacturing Processes ◽  
Laser Melting ◽  
Manufacturing Costs ◽  
Process Reliability ◽  
High Degree ◽  
Design Freedom ◽  
Processing Steps

Additive Fertigungsverfahren zeichnen sich durch große Gestaltungsfreiheit aus, welche die Herstellung komplexer Bauteile ermöglicht. Angesichts hoher Fertigungskosten ist die Prozesssicherheit nachgeordneter Bearbeitungsschritte (wie zum Beispiel die Gewindefertigung) von großer Bedeutung. Der Artikel stellt die Ergebnisse einer Untersuchungsreihe vor, die unterschiedliche Ansätze der Gewindefertigung in Bauteilen aus Stahl behandelt, die mittels Selektivem Laserschmelzverfahren gefertigt wurden.   Additive manufacturing processes are characterized by a high degree of design freedom to enablet the production of complex components. To reduce manufacturing costs, the process reliability of downstream processing steps (e. g. thread production) is of great importance. This article presents the results of a series of investigations dealing with different approaches to thread production in steel components manufactured by selective laser melting

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