scholarly journals Study on the variation of the argon volume and the degree of loading of the paper filter in a 3D printer type MYSINT 100 during the process of selective laser melting of metal powders (SLM)

2020 ◽  
pp. 272-277
Author(s):  
Alexandru-Constantin Tulică ◽  
Corneliu-Nicolae Drugă
Keyword(s):  
Selective Laser Melting ◽  
3D Printer ◽  
Metal Powders ◽  
Laser Melting ◽  
Paper Filter

scholarly journals Thermodynamic Behavior of Fe-Mn and Fe-Mn-Ag Powder Mixtures during Selective Laser Melting

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 234
Author(s):  
Jakob Kraner ◽  
Jožef Medved ◽  
Matjaž Godec ◽  
Irena Paulin
Keyword(s):  
Selective Laser Melting ◽  
Manganese Oxides ◽  
Elevated Temperatures ◽  
Manganese Content ◽  
Chemical Compositions ◽  
Metal Powders ◽  
Laser Melting ◽  
Powder Mixtures ◽  
Ε Martensite ◽  
The Impact

Additive manufacturing is a form of powder metallurgy, which means the properties of the initial metal powders (chemical composition, powder morphology and size) impact the final properties of the resulting parts. A complete characterization, including thermodynamic effects and the behavior of the metal powders at elevated temperatures, is crucial when planning the manufacturing process. The analysis of the Fe-Mn and Fe-Mn-Ag powder mixtures, made from pure elemental powders, shows a high susceptibility to sintering in the temperature interval from 700 to 1000 °C. Here, numerous changes to the manganese oxides and the αMn to βMn transformation occurred. The problems of mechanically mixed powders, when using selective laser melting, were highlighted by the low flowability, which led to a less controllable process, an uncontrolled arrangement of the powder and a large percentage of burnt manganese. All this was determined from the altered chemical compositions of the produced parts. The impact of the increased manganese content on the decreased probability of the transformation from γ-austenite to ε-martensite was confirmed. The ε-martensite in the microstructure increased the hardness of the material, but at the same time, its magnetic properties reduce the usefulness for medical applications. However, the produced parts had comparable elongations to human bone.

Modeling, Simulation and Experimental Validation of Heat Transfer During Selective Laser Melting

2015 ◽  
Author(s):  
Mohammad Masoomi ◽  
Xiang Gao ◽  
Scott M. Thompson ◽  
Nima Shamsaei ◽  
Linkan Bian ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Heat Fluxes ◽  
Transient Temperature ◽  
Thermal Gradients ◽  
Layer By Layer ◽  
Metal Powders ◽  
Laser Melting ◽  
Powder Bed

Selective Laser Melting (SLM), a laser powder-bed fusion (PBF-L) additive manufacturing method, utilizes a laser to selectively fuse adjacent metal powders. The powders are aligned in a bed that moves vertically to allow for layer-by-layer part construction-Process-related heat transfer and thermal gradients have a strong influence on the microstructural features, and subsequent mechanical properties, of the parts fabricated via SLM. In order to understand and control the heat transfer inherent to SLM, and to ensure high quality parts with targeted microstructures and mechanical properties, comprehensive knowledge of the related energy and mass transport during manufacturing is required. In this study, the transient temperature distribution within and around parts being fabricated via SLM is numerically simulated and the results are provided to aid in quantify the SLM heat transfer. In order to verify simulation output, and to estimate actual thermal gradients and heat transfer, experiments were separately conducted within a SLM machine using a substrate with embedded thermocouples. The experiments focused on characterizing heat fluxes during initial deposition on an initially-cold substrate and during the fabrication of a thin-walled structure built via stainless steel 17-4 powders. Results indicate that it is important to model heat transfer thorough powder bed as well as substrate.

Optical Monitoring and Numerical Simulation of Temperature Distribution at Selective Laser Melting of Ti6Al4V Alloy

2015 ◽  
Vol 828-829 ◽  
pp. 474-481 ◽  
Author(s):  
Ivan Zhirnov ◽  
Ina Yadroitsava ◽  
Igor Yadroitsev
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Selective Laser Melting ◽  
Ti6al4v Alloy ◽  
Advanced Technology ◽  
Temperature Fields ◽  
Optical Monitoring ◽  
Metal Powders ◽  
Laser Melting ◽  
Ir Camera

Selective laser melting (SLM) is a modern method for producing objects with complex shape and fine structures in one working cycle from metal powders. Combination of the advanced technology of SLM with unique properties of Ti6Al4V alloy allows creating complex 3D objects for medicine or aerospace industry. Since properties of SLM parts depend on the geometrical characteristics of tracks and their cohesion, optical monitoring is actually used to for control the process. Temperature gradient determines the microstructure and mechanical properties of the SLM part, so studies about temperature fields are primarily important. On-line monitoring during laser scanning of Ti6Al4V alloy and formation of a single track in real-time with high-speed IR camera was studied. Numerical simulation allowed estimation the temperature distribution during processing. Conclusion regarding control system based on the online monitoring of deviations of the signal from IR camera during the SLM process was done.

Investigation of Sectoral Scanning in Selective Laser Melting

2010 ◽  
Author(s):  
Evren Yasa ◽  
Jan Deckers ◽  
Jean-Pierre Kruth ◽  
Marleen Rombouts ◽  
Jan Luyten
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Laser Beam ◽  
Surface Quality ◽  
Selective Laser Melting ◽  
Random Order ◽  
Laser Source ◽  
Metal Powders ◽  
Laser Melting ◽  
Powder Bed

Selective laser melting (SLM), a powder metallurgical (PM) additive manufacturing (AM) technology, is able to produce fully functional parts directly from standard metal powders without using any intermediate binders or any additional post-processing steps. During the process, a laser beam selectively scans a powder bed according to the CAD data of the part to be produced and completely melts the powder particles together. Stacking and bonding two-dimensional powder layers in this way, allows production of fully dense parts with any geometrical complexity. The scanning of the powder bed by the laser beam can be achieved in several different ways, one of which is island or sectoral scanning. In this way, the area to be scanned is divided in small square areas (‘sectors’) which are scanned in a random order. This study is carried out to explore the influence of sectoral scanning on density, surface quality, mechanical properties and residual stresses formed during SLM. The experiments are carried out on a machine with an Nd:YAG laser source using AISI 316L stainless steel powder. As a result of this experimental study, it is concluded that sectoral scanning has some advantages such as lower residual stresses and better surface quality. However, the selection of parameters related to sectoral scanning is a critical task since it may cause aligned porosity at the edges between sectors or scanned tracks, which is very undesired in terms of mechanical properties.

Accelerated Corrosion Analysis of AlSi10Mg Alloy Manufactured by Selective Laser Melting (SLM)

2018 ◽  
Vol 69 (4) ◽  
pp. 975-981 ◽  
Author(s):  
Camil Lancea ◽  
Lucia Antoneta Chicos ◽  
Sebastian Marian Zaharia ◽  
Mihai Alin Pop ◽  
Augustin Semenescu ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
High Salinity ◽  
Metal Powders ◽  
High Power Laser ◽  
Optical Analysis ◽  
Laser Melting ◽  
Power Laser ◽  
Accelerated Corrosion ◽  
3D Geometry ◽  
Complex Parts

The Selective Laser Melting (SLM) technology uses metal powders as building material which is melted and welded together using a high-power laser in order to obtain quick configuration of complex parts, most often for testing them. Another advantage of this method is the fact that allows obtaining any 3D geometry of the parts, even parts that cannot be processed through conventional manufacturing procedures. In this work were performed a number of tests for accelerated corrosion of AlSi10Mg alloy specimens in order to determine their mean life in the conditions of their use in a high salinity environment. For specimens, optical analysis was used the SEM microscope which has the advantage of obtaining an enlarged image of the investigated objects without processing. Following these analyses, it has been determined the mass loss of specimens due to corrosion.

Factors of strength increasing of metals produced by selective laser melting of powders

2019 ◽  
pp. 68-75 ◽  
Author(s):  
B. K. Barakhtin ◽  
A. S. Zhukov ◽  
V. V. Bobyr ◽  
I. V. Shakirov ◽  
P. A. Kuznetsov
Keyword(s):  
Chemical Composition ◽  
Selective Laser Melting ◽  
Mechanical Tests ◽  
Strength Characteristics ◽  
Strength Increase ◽  
Metal Powders ◽  
Laser Melting ◽  
Standard Samples ◽  
Ultrafine Grained ◽  
Identical Chemical Composition

Standard samples of metal powders of various chemical composition were made for mechanical tests by selective laser melting. The paper describes an increase in strength characteristics of all samples made by melting comparing with similar parameters of monolithic samples of identical chemical composition. It is established that ultrafine-grained structure and condensation of nanoparticles could be cosidered factors of strength increase.

Progress on Investigation of Pores During Selective Laser Melting of Metal Powders and Future Work Discussion

2011 ◽  
Vol 291-294 ◽  
pp. 3088-3094
Author(s):  
Jin Hui Liu ◽  
Wen Juan Xie ◽  
Qing Song Wei ◽  
Li Wang
Keyword(s):  
Selective Laser Melting ◽  
Physical And Mechanical Properties ◽  
Porous Metal ◽  
Complex Structures ◽  
Metal Powders ◽  
Porous Metals ◽  
Laser Melting ◽  
Metal Structures ◽  
Metal Parts ◽  
Future Work

Pores are always considered as a kind of defect during manufacturing metal parts via many conventional processes. But porous metals have outstanding physical and mechanical properties which providing them double natures of function and structure, and are applied in many fields of science and technology. Selective laser melting (SLM), developed within current years, has the advantages of producing metal parts with complex structures, and can be used to manufacture complex structures of any kind theoretically. A new method of making porous complicated metal structures via SLM is put forward. Then, the meaning of this method, research advance and future work discussion are presented in this paper, which lays a method foundation for future study and build a new field for both porous metal parts and SLM technology.

A Study on Effect of Different Process Parameters on the Quality of Overhang Surface Produced by Selective Laser Melting

2018 ◽  
Author(s):  
Sagar Sarkar ◽  
Ankit Porwal ◽  
Nuthalapati Yaswanth ◽  
Ashish Kumar Nath
Keyword(s):  
Aspect Ratio ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Support Structures ◽  
Metal Powders ◽  
Laser Melting ◽  
Scanning Strategy ◽  
Support Structure ◽  
Laser Process

Selective Laser Melting process enables production of geometrically complex parts directly from CAD model by melting metal powders layer by layer. For successful building of parts, some auxiliary structures namely support structures are also built to ensure proper heat conduction from actual parts to be built to the base plate. Support structures are needed if there are overhang surfaces in the design of the part. If the design of the part is very complex and features many overhang surfaces, then too many supports get generated. After building the part, these support structures need to be removed properly to get desired geometrical features and it may deteriorate the surface quality from where supports are removed. Sometimes removal of support structures becomes very difficult specially for parts having internal features. In this study, first effect of inclined angle, aspect ratio and different scanning strategies on the quality of overhang surfaces produced without any support structure under constant laser power and scan speed has been investigated. Scanning Electron Microscopy (SEM) images of overhang surfaces have been analyzed to investigate the presence of warping and uneven fused edges if any. It was found that with increase in inclined angles and aspect ratio, warping and presence of uneven fused edges increases. Rotational scanning strategy found to be better than linear alternate scanning strategy for reduced uneven fused edges formation and warping. Results show an overhang without any support structure can be built successfully with a single laser process parameters upto 25.343 degree which is less than theoretical critical angle of 26.565 degree. Further, it has been shown, using a novel strategy of building overhang with multiple laser process parameters, it is possible to build overhang even upto 24.132 degree.

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