Discrete element method model calibration and validation for the spreading step of the powder bed fusion process to predict the quality of the layer surface (Open Access)--颗粒学报PARTICUOLOGY

Lupo, M., Zinatlou Ajabshir, S., Sofia, D., Barletta, D., & Poletto, M. (2024). Discrete element method model calibration and validation for the spreading step of the powder bed fusion process to predict the quality of the layer surface. Particuology, 94, 261-273. https://doi.org/10.1016/j.partic.2024.08.010

Discrete element method model calibration and validation for the spreading step of the powder bed fusion process to predict the quality of the layer surface (Open Access)

Marco Lupo¹, Sina Zinatlou Ajabshir, Daniele Sofia², Diego Barletta, Massimo Poletto^*

Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, SA, Italy

10.1016/j.partic.2024.08.010

Volume 94, November 2024, Pages 261-273

Received 19 May 2024, Revised 31 July 2024, Accepted 22 August 2024, Available online 31 August 2024, Version of Record 9 September 2024.

E-mail: mpoletto@unisa.it

Highlights

• A model according to discrete element model was developed to simulate the powder spreading in the powder bed fusion process.

• Surface energy of the model particles was estimated from powder shear testing experiments.

• Particle rolling friction was calibrated considering the bulk density of the layer.

• Image analysis was used to compare experimental and simulated powder layers.

• The model was validated by comparing the model and the experimental wavelet power spectra of the surface.

Abstract

A Discrete Element Method model, including interparticle cohesive forces, was calibrated and validated to develop a tool to predict the powder layer’s quality in the powder bed fusion process. An elastic contact model was used to describe cohesive interparticle interactions. The surface energy of the model particles was estimated by assuming that the pull-off force should provide the strength of the material evaluated at low consolidation with shear test experiments. The particle rolling friction was calibrated considering the bulk density of the layer produced by the spreading tool. The model was validated with the experiments by comparing the wavelet power spectra obtained with the simulations with those of the experimental layers illuminated by grazing light. The calibration proposed in this study demonstrated superior performance compared to our previous methods, which relied on measuring the angle of repose and unconfined yield strength.

Graphical abstract

Keywords

Additive manufacturing; Powder bed fusion; Laser sintering; Powder spreading; Discrete element method; Wavelet transform

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