Selective Laser Sintering of Resin-Coated Sands—Part I: The Laser-Material Interaction

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Fabrizio Quadrini ◽  
Loredana Santo
Keyword(s):  
Focal Spot ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Laser Source ◽  
Layer By Layer ◽  
Sintering Process ◽  
New Approach ◽  
Laser Material ◽  
Definition Of ◽  
Material Interaction

Selective laser sintering of precoated sands is a process utilized to produce molds and cores for rapid casting by adding sand layer by layer and heating it using a laser beam. During the process, the resin flows and binds the grains; subsequently, an oven is used for the postcuring treatment to complete the curing of the resin. The aim of this paper was to study the laser-material interaction using a diode laser to directly obtain the material consolidation. It was the first step in the definition of a new approach for process investigation and innovation. Two main aspects were investigated with the laser source in a standstill position: first, the influence of the laser power, the location of the focal spot, and the exposure time on sand consolidation; second, the shape and dimension of cured samples depending on the process parameters. The experimental data, in terms of weight and size of the hardened sands, were analyzed, and a master curve was found. In Part II of this paper the selective laser sintering process will be implemented to produce shells.

scholarly journals Simulation of the Heat Laser of the Selective Laser Sintering Process of the Polyamide12

2021 ◽  
Vol 297 ◽  
pp. 01050
Author(s):  
Hanane Yaagoubi ◽  
Hamid Abouchadi ◽  
Mourad Taha Janan
Keyword(s):  
Heat Flux ◽  
3D Printing ◽  
Selective Laser Sintering ◽  
3D Models ◽  
Laser Sintering ◽  
Laser Source ◽  
Sintering Process ◽  
Powder Bed ◽  
Source Models ◽  
Flux Diffusion

Laser sintering sintering is one of the most widely used 3D printing technologies, in which it transforms 3D models into authentic parts with generally excellent workmanship, the test today is to ensure the unmatched nature of the item produced, therefore hypothetically to understand and predict the thermal history in this process, the thermal models must be exact and fair, In this article, the consideration will be focused on the different models of heat flux diffusion, in the bibliography, some formulas Numbers that describe the transport of the heat source out of the powder bed have been found. A comparison between its laser source models will be established. The re-modeling takes place in MATLAB using the parameters of polyamide12.

scholarly journals Process Phenomena and Material Properties in Selective Laser Sintering of Polymers: A Review

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 183
Author(s):  
Federico Lupone ◽  
Elisa Padovano ◽  
Francesco Casamento ◽  
Claudio Badini
Keyword(s):  
Material Properties ◽  
Complex Geometry ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Laser Source ◽  
Layer By Layer ◽  
Powder Bed ◽  
Complex Process ◽  
And Performance ◽  
Physical Phenomena

Selective laser sintering (SLS) is a powder bed fusion technology that uses a laser source to melt selected regions of a polymer powder bed based on 3D model data. Components with complex geometry are then obtained using a layer-by-layer strategy. This additive manufacturing technology is a very complex process in which various multiphysical phenomena and different mechanisms occur and greatly influence both the quality and performance of printed parts. This review describes the physical phenomena involved in the SLS process such as powder spreading, the interaction between laser beam and powder bed, polymer melting, coalescence of fused powder and its densification, and polymer crystallization. Moreover, the main characterization approaches that can be useful to investigate the starting material properties are reported and discussed.

scholarly journals Online Monitoring Based on Temperature Field Features and Prediction Model for Selective Laser Sintering Process

2018 ◽  
Vol 8 (12) ◽  
pp. 2383 ◽  
Author(s):  
Zhehan Chen ◽  
Xianhui Zong ◽  
Jing Shi ◽  
Xiaohua Zhang
Keyword(s):  
Temperature Field ◽  
Prediction Model ◽  
Selective Laser Sintering ◽  
Principal Component ◽  
Laser Sintering ◽  
Support Vector ◽  
Sintering Process ◽  
Metal Materials ◽  
Key Features ◽  
The Mathematical Model

Selective laser sintering (SLS) is an additive manufacturing technology that can work with a variety of metal materials, and has been widely employed in many applications. The establishment of a data correlation model through the analysis of temperature field images is a recognized research method to realize the monitoring and quality control of the SLS process. In this paper, the key features of the temperature field in the process are extracted from three levels, and the mathematical model and data structure of the key features are constructed. Feature extraction, dimensional reduction, and parameter optimization are realized based on principal component analysis (PCA) and support vector machine (SVM), and the prediction model is built and optimized. Finally, the feasibility of the proposed algorithms and model is verified by experiments.

Characteristics of Nanopatterns and the Associated Thermal Mechanisms During Near Field Laser-Material Interaction of Nanosecond Laser on Different Targets

2009 ◽  
Author(s):  
Vijay M. Sundaram ◽  
Sy-Bor Wen
Keyword(s):  
Near Field ◽  
Target Material ◽  
Optical Microscope ◽  
Laser Source ◽  
Nanosecond Laser ◽  
Metallic Surfaces ◽  
Experimental Conditions ◽  
Laser Material ◽  
Material Conditions ◽  
Material Interaction

Nano-patterns are generated on semiconducting and metallic surfaces through coupling an apertured near field scanning optical microscope (NSOM) with a pulsed laser source in this study. To understand the dominant mechanisms for the generation of the nano-patterns, a series of experimental measurement of the size and shape of nano-patterns generated on targets under different experimental conditions with different targets is conducted. The characteristic dimensions of nano-patterns show dependence on optical properties of the target material. The qualitative trend of the variation of nano-patterns as a function of laser and material conditions indicates that the dominant mechanisms for the generation of nano-patterns through a combination of nanosecond laser and an apertured NSOM under different conditions studied is near field laser-material interaction.

Physical Modeling for Selective Laser Sintering Process

2017 ◽  
Vol 17 (2) ◽  
Author(s):  
Arash Gobal ◽  
Bahram Ravani
Keyword(s):  
Physical Modeling ◽  
Large Scale ◽  
Selective Laser Sintering ◽  
Powdered Material ◽  
Laser Sintering ◽  
Industrial Applications ◽  
Transient Temperature ◽  
Sintering Process ◽  
Powder Bed ◽  
Selective Heating

The process of selective laser sintering (SLS) involves selective heating and fusion of powdered material using a moving laser beam. Because of its complicated manufacturing process, physical modeling of the transformation from powder to final product in the SLS process is currently a challenge. Existing simulations of transient temperatures during this process are performed either using finite-element (FE) or discrete-element (DE) methods which are either inaccurate in representing the heat-affected zone (HAZ) or computationally expensive to be practical in large-scale industrial applications. In this work, a new computational model for physical modeling of the transient temperature of the powder bed during the SLS process is developed that combines the FE and the DE methods and accounts for the dynamic changes of particle contact areas in the HAZ. The results show significant improvements in computational efficiency over traditional DE simulations while maintaining the same level of accuracy.

scholarly journals Hybrid Approaches for Selective Laser Sintering by Building on Dissimilar Materials

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5285
Author(s):  
Babette Goetzendorfer ◽  
Thomas Mohr ◽  
Ralf Hellmann
Keyword(s):  
Substrate Surface ◽  
Selective Laser Sintering ◽  
Dissimilar Materials ◽  
Polyamide 6 ◽  
Laser Sintering ◽  
New Approach ◽  
Metallic Substrates ◽  
Polyamide 12 ◽  
Melting Temperatures ◽  
Hybrid Approaches

We introduced a new approach in selective laser sintering for hybrid multicomponent systems by fabricating the sintered polyamide 12 (PA12) part directly onto a similar (PA12) or dissimilar (polyamide 6 (PA6) and tool steel 1.2709) joining partner. Thus, the need for adhesive substances or joining pressure was completely circumvented, leading to the possibility of pure hybrid lightweight bi-polymer or metal–polymer systems. By taking advantage of the heating capabilities of the sinter laser regarding the substrate surface, different exposure strategies circumvented the lack of overlapping melting temperatures of dissimilar polymers. Therefore, even sintering on non-PA12 polymers was made possible. Finally, the transfer on metallic substrates—made up by selective laser melting (SLM)—was successfully performed, closing the gap between two powder-based additive processes, selective laser sintering (SLS) and SLM.

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