Three-dimensional transient finite element analysis of the selective laser sintering process

Dong, Lin; Makradi, A.; Ahzi, Saı̈d; Rémond, Yves

doi:10.1016/j.jmatprotec.2008.02.040

Cited by 190 publications

(95 citation statements)

References 18 publications

(28 reference statements)

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“…Kolossov et al [94] modelled the heat transfer and thermal field using a nonlinear 3D model, which took into consideration the thermal characteristics of bulk material, such as thermal conductivity and heat capacity and the thermal history of the material in each step. Dong et al [53] created a 3D FEA model to predict statistically the temperature and density distribution in the SLS of polycarbonate. The parameters analysed include the laser beam velocity, laser power and laser diameter, and the results have been verified against experimental values found on related literature.…”

Section: Laser Meltingmentioning

confidence: 99%

Additive manufacturing methods and modelling approaches: a critical review

Bikas

Stavropoulos

Chryssolouris

2015

Int J Adv Manuf Technol

1,174

443

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Additive manufacturing is a technology rapidly expanding on a number of industrial sectors. It provides design freedom and environmental/ecological advantages. It transforms essentially design files to fully functional products. However, it is still hampered by low productivity, poor quality and uncertainty of final part mechanical properties. The root cause of undesired effects lies in the control aspects of the process. Optimization is difficult due to limited modelling approaches. Physical phenomena associated with additive manufacturing processes are complex, including melting/ solidification and vaporization, heat and mass transfer etc. The goal of the current study is to map available additive manufacturing methods based on their process mechanisms, review modelling approaches based on modelling methods and identify research gaps. Later sections of the study review implications for closed-loop control of the process.

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Section: Laser Meltingmentioning

confidence: 99%

Additive manufacturing methods and modelling approaches: a critical review

Bikas

Stavropoulos

Chryssolouris

2015

Int J Adv Manuf Technol

1,174

443

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“…Ryder et al [7] extended the previous model to 2 dimensions, incorporating also the effect of a spatially dependent conductivity and porosity. Other research groups have further studied other related phenomena such as Z growth [8], thermal degradation [9], polymer densification [10] and temperature evolution during laser scanning [11]. One of the main limitations for SLS polymer processability is related to the so-called warpage or curling effect that develops when the polymer starts crystallizing.…”

Section: Introductionmentioning

confidence: 99%

Simulation of warpage induced by non-isothermal crystallization of co-polypropylene during the SLS process

Amado

Schmid

Wegener

2015

AIP Conference Proceedings

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Abstract. Polymer processing using Additive Manufacturing Technologies (AM) has experienced a remarkable growth during the last years. The application range has been expanding rapidly, particularly driven by the so-called consumer 3D printing sector. However, for applications demanding higher requirements in terms of thermo-mechanical properties and dimensional accuracy the long established AM technologies such as Selective Laser Sintering (SLS) do not depict a comparable development. The higher process complexity hinders the number of materials that can be currently processed and the interactions between the different physics involved have not been fully investigated. In case of thermoplastic materials the crystallization kinetics coupled to the shrinkage strain development strongly influences the stability of the process. Thus, the current investigation presents a transient Finite Element simulation of the warpage effect during the SLS process of a new developed polyolefin (co-polypropylene) coupling the thermal, mechanical and phase change equations that control the process. A thermal characterization of the material was performed by means of DSC, integrating the Nakamura model with the classical Hoffmann-Lauritzen theory. The viscoelastic behavior was measured using a plate-plate rheometer at different degrees of undercooling and a phase change-temperature superposition principle was implemented. Additionally, for validation porpoises the warpage development of the first sintered layers was captured employing an optical device. The simulation results depict a good agreement with experimental measurements of deformation, describing the high sensitivity of the geometrical accuracy of the sintered parts related to the processing conditions.

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“…The process continues, more slices are added and sintered and will cause the conduction distance, d for the heat conduction to increase. The longer travelling distance can increase the thermal resistance, leading to a higher transfer period, thus reducing the rate of heat transfer [38]. Low rates of heat transfer means the thermal energy will be stored for longer periods, providing sufficient heat to completely melt and fuse metal powders, thus reducing the porosity.…”

Section: Optical Microscopy Analysismentioning

confidence: 99%

Electrical conductivity and porosity in stainless steel 316L scaffolds for electrochemical devices fabricated using selective laser sintering

Ibrahim

Brandon

2016

Materials & Design

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Battery electrode microstructures must be porous, to provide a large active surface area to facilitate fast charge transfer kinetics. In this work, we describe how a novel porous electrode scaffold, made from stainless steel 316L powder can be fabricated using selective laser sintering by proper selection of process parameters. Porosity, electrical conductivity and optical microscopy measurements were used to investigate the properties of fabricated samples. Our results show that a laser energy density between 1.50-2.00 J/mm 2 leads to a partial laser sintering mechanism where the powder particles are partially fused together, resulting in the fabrication of electrode scaffolds with 10% or higher porosity. The sample fabricated using 2.00 J/mm 2 energy density (60W -1200 mm/s) exhibited a good electrical conductivity of 1.80 x 10 6 S/m with 15.61% of porosity. Moreover, we have observed the porosity changes across height for the sample fabricated at 60W and 600 mm/s, 5.70% from base and increasing to 7.12% and 9.89% for each 2.5 mm height toward the top surface offering graded properties ideal for electrochemical devices, due to the changing thermal boundary conditions. These highly porous electrode scaffolds can be used as an electrode in electrochemical devices, potentially improving energy density and life cycle.

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Three-dimensional transient finite element analysis of the selective laser sintering process

Cited by 190 publications

References 18 publications

Additive manufacturing methods and modelling approaches: a critical review

Additive manufacturing methods and modelling approaches: a critical review

Simulation of warpage induced by non-isothermal crystallization of co-polypropylene during the SLS process

Electrical conductivity and porosity in stainless steel 316L scaffolds for electrochemical devices fabricated using selective laser sintering

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