Melt Pool Evolution in High-Power Selective Laser Melting of Nickel-Based Alloy

2021 ◽  
pp. 142-148
Author(s):  
Borisov Evgenii ◽  
Starikov Kirill ◽  
Popovich Anatoly ◽  
Popovich Vera
Keyword(s):  
Selective Laser Melting ◽  
High Power ◽  
Laser Melting ◽  
Melt Pool ◽  
Nickel Based Alloy

scholarly journals Beam Diameter Dependence of Performance in Thick-Layer and High-Power Selective Laser Melting of Ti-6Al-4V

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1237 ◽  
Author(s):  
Wentian Shi ◽  
Yude Liu ◽  
Xuezhi Shi ◽  
Yanjun Hou ◽  
Peng Wang ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
High Power ◽  
Large Diameter ◽  
Thick Layer ◽  
Beam Diameter ◽  
Laser Melting ◽  
Power Laser ◽  
Beam Laser ◽  
Melt Pool ◽  
Thick Layers

A 400 W high-power laser was used to fabricate 200-µm-thick Ti-6Al-4V samples to evaluate the effects of small (50 μm) and large (200 μm) beam diameter on density, microstructure and mechanical properties. A series of single-track experiments demonstrated that it was challenging for the small-beam laser to fabricate smooth and defect-free scan tracks. A larger beam diameter efficiently avoided process instability and provided a more stable and uniform melt pool. By increasing the beam diameter, the density of multilayer samples reached 99.95% of the theoretical value, which is much higher than that achieved with the small beam diameter. However, it was difficult to completely eliminate defects due to serious spatter and evaporation. Moreover, all of the generated samples had relatively coarse surfaces. For the large beam diameter of 200 µm, the optimal yield strength, ultimate tensile strength and elongation were 1150 MPa, 1200 MPa and 8.02%, respectively. In comparison, the small beam diameter of 50 µm resulted in values of 1035 MPa, 1100 MPa and 5.91%, respectively. Overall, the large-diameter laser is more suitable for high-power selective laser melting (SLM) technology, especially for thick layers.

In-situ capture of melt pool signature in selective laser melting using U-Net-based convolutional neural network

2021 ◽  
Vol 68 ◽  
pp. 347-355
Author(s):  
Qihang Fang ◽  
Zhenbiao Tan ◽  
Hui Li ◽  
Shengnan Shen ◽  
Sheng Liu ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Selective Laser Melting ◽  
Laser Melting ◽  
Melt Pool

scholarly journals Prediction of lack of fusion porosity in selective laser melting based on melt pool monitoring data

2019 ◽  
Vol 25 ◽  
pp. 347-356 ◽  
Author(s):  
Sam Coeck ◽  
Manisha Bisht ◽  
Jan Plas ◽  
Frederik Verbist
Keyword(s):  
Selective Laser Melting ◽  
Monitoring Data ◽  
Laser Melting ◽  
Lack Of Fusion ◽  
Melt Pool

scholarly journals Influence of the Manufacturing Parameters in Selective Laser Melting on Properties of Aluminum Alloy AlSi7Mg0.6 (A357)

2021 ◽  
Vol 45 (1) ◽  
pp. 1-10
Author(s):  
Arnold Mauduit ◽  
Hervé Gransac ◽  
Sébastien Pillot
Keyword(s):  
Aluminum Alloy ◽  
Theoretical Model ◽  
Selective Laser Melting ◽  
Chemical Elements ◽  
Laser Melting ◽  
Operating Modes ◽  
Melt Pool ◽  
Section Area ◽  
Maximum Temperatures ◽  
Conduction Mode

Various selective laser melting (SLM) configurations (8 in all) were tested on aluminum alloy AlSi7Mg0.6 by making single tracks on parallelepipeds specimens. We used an energy balance as a means of connecting the machine parameters (power, speed, etc.) of the 8 configurations to the morphology (geometry) of the single tracks. On this basis, we correlated the width, depth and especially the section area of the melt pool (single track) to the linear energy density. We were also able to assess the absorption coefficient of the aluminum alloy AlSi7Mg0.6 as a function of the temperature. The study was then focused on the microstructure and the possible impacts on the material properties including on the mechanical characteristics and the anisotropy observed in literature based on the build direction. Evidence suggests that the Hall-Petch relation can be used to explain this anisotropy. The thermal analysis highlighted two laser operating modes: the keyhole mode and the conduction mode. These modes have also been described via the morphology of the single tracks. Finally, a comparison between Rosenthal’s theoretical model (in the case of the conduction mode) and actual conditions was proposed by the obtained geometry of the single tracks as well as the cooling speeds calculated and measured using the dendrite arm spacing (DAS). The maximum temperatures achieved were also assessed by Rosenthal’s theoretical model which made it possible to explain the evaporation of some chemical elements during the manufacturing of the aluminum alloy through SLM.

scholarly journals Texture control of 316L parts by modulation of the melt pool morphology in selective laser melting

2019 ◽  
Vol 264 ◽  
pp. 21-31 ◽  
Author(s):  
Olivier Andreau ◽  
Imade Koutiri ◽  
Patrice Peyre ◽  
Jean-Daniel Penot ◽  
Nicolas Saintier ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Laser Melting ◽  
Melt Pool

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.

scholarly journals Thermo-Fluid-Dynamic Modeling of the Melt Pool during Selective Laser Melting for AZ91D Magnesium Alloy

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4157
Author(s):  
Hongyao Shen ◽  
Jinwen Yan ◽  
Xiaomiao Niu
Keyword(s):  
Temperature Distribution ◽  
Magnesium Alloy ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Large Temperature ◽  
Fe Model ◽  
Laser Melting ◽  
Az91d Magnesium Alloy ◽  
Melt Pool ◽  
Flow Activity

A three dimensional finite element model (FEM) was established to simulate the temperature distribution, flow activity, and deformation of the melt pool of selective laser melting (SLM) AZ91D magnesium alloy powder. The latent heat in phase transition, Marangoni effect, and the movement of laser beam power with a Gaussian energy distribution were taken into account. The influence of the applied linear laser power on temperature distribution, flow field, and the melt-pool dimensions and shape, as well as resultant densification activity, was investigated and is discussed in this paper. Large temperature gradients and high cooling rates were observed during the process. A violent flow occurred in the melt pool, and the divergent flow makes the melt pool wider and longer but shallower. With the increase of laser power, the melt pool’s size increases, but the shape becomes longer and narrower. The width of the melt pool in single-scan experiment is acquired, which is in good agreement with the results predicted by the simulation (with error of 1.49%). This FE model provides an intuitive understanding of the complex physical phenomena that occur during SLM process of AZ91D magnesium alloy. It can help to select the optimal parameters to improve the quality of final parts and reduce the cost of experimental research.

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