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Article
Publication date: 18 December 2024

Yancheng Zhang, Hugo Behlal, Charles-André Gandin, Oriane Senninger, Gildas Guillemot and Michel Bellet

This paper aims to report on a homogenized model for the anisotropic thermal conductivity of support structures constructed by the laser powder bed fusion (L-PBF) process, and its…

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Abstract

Purpose

This paper aims to report on a homogenized model for the anisotropic thermal conductivity of support structures constructed by the laser powder bed fusion (L-PBF) process, and its application to the numerical simulation of the L-PBF process.

Design/methodology/approach

Considering both analytical and numerical approaches, the model is developed across a temperature interval encompassing the entire L-PBF process. Subsequently, the homogenized material properties are incorporated into a thermal finite element model (FEM) of the L-PBF process to consider the effects of the support structures, taking into account their anisotropic properties.

Findings

The simulation results of the L-PBF process indicate that the support structures act as a thermal barrier, retaining more heat in part compared to direct printing on the substrate. The implementation of homogeneous thermal conductivity in the L-PBF process simulation demonstrates its efficiency and potential application to better control heat transfer during part construction.

Originality/value

The homogenized anisotropic thermal conductivity of a support structure has been characterized by both analytical and numerical approaches. Such homogenized anisotropic tensor was implemented in L-PBF numerical simulation. This showed a strong influence of the supports on the temperature distribution and evolution.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 35 no. 1
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 29 September 2021

Yaasin Abraham Mayi, Alexis Queva, Morgan Dal, Gildas Guillemot, Charlotte Metton, Clara Moriconi, Patrice Peyre and Michel Bellet

During thermal laser processes, heat transfer and fluid flow in the melt pool are primary driven by complex physical phenomena that take place at liquid/vapor interface. Hence…

564

Abstract

Purpose

During thermal laser processes, heat transfer and fluid flow in the melt pool are primary driven by complex physical phenomena that take place at liquid/vapor interface. Hence, the choice and setting of front description methods must be done carefully. Therefore, the purpose of this paper is to investigate to what extent front description methods may bias physical representativeness of numerical models of laser powder bed fusion (LPBF) process at melt pool scale.

Design/methodology/approach

Two multiphysical LPBF models are confronted: a Level-Set (LS) front capturing model based on a C++ code and a front tracking model, developed with COMSOL Multiphysics® and based on Arbitrary Lagrangian–Eulerian (ALE) method. To do so, two minimal test cases of increasing complexity are defined. They are simplified to the largest degree, but they integrate multiphysics phenomena that are still relevant to LPBF process.

Findings

LS and ALE methods provide very similar descriptions of thermo-hydrodynamic phenomena that occur during LPBF, providing LS interface thickness is correctly calibrated and laser heat source is implemented with a modified continuum surface force formulation. With these calibrations, thermal predictions are identical. However, the velocity field in the LS model is systematically underestimated compared to the ALE approach, but the consequences on the predicted melt pool dimensions are minor.

Originality/value

This study fulfils the need for comprehensive methodology bases for modeling and calibrating multiphysical models of LPBF at melt pool scale. This paper also provides with reference data that may be used by any researcher willing to verify their own numerical method.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

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