Modeling of Powder Bed Deformation in the Binder Jetting Technology

• Published in: Powder metallurgy and metal ceramics Vol. 61; no. 1-2; pp. 1 - 8
• Main Authors: Maidaniuk, O.P., Maximenko, A.L., Olumor, D., Torresani, E., Shtern, M.B., Olevsky, E.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2022; Springer; Springer Nature B.V
• Subjects: Analysis; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Continuum modeling; Deformation; Density distribution; Deposition; Diameters; Discrete element method; Distortion; Empirical equations; Energy dissipation; Glass; Granular materials; Granular media; Materials Science; Metallic Materials; Natural Materials; Particle interactions; Powder beds; Powders; Rapid prototyping; Shear strain; Size effects; Theory and Technology of Forming Processes; Thickness; Thin films; deformation; shape reproduction; discrete element modeling; powder deposition; binder jetting
• ISSN: 1068-1302; 1573-9066
• DOI: 10.1007/s11106-022-00289-7

Discrete element modeling of granular media with the binder jetting additive technique is discussed. The main specific feature of this technique is additive buildup of a green body with thin powder layers that are bonded together with a binder deposited on the areas that correspond to the preset shape of the green body. The technique requires that thickness of the added powder layers is less than three particle diameters. This leads to size effects and precludes the application of continuum modeling. Discrete powder modeling allows the particle rearrangement in powder deposition and spreading in thin layers to be predicted and the density redistribution and shear strains in the powder layers to be evaluated. To ensure that the added layers are uniform, the powder is spread with a blade moving along the powder bed. Distortions of the bonded subsurface elements of the powder bed depend on the blade width: wide blades produce more significant distortions than narrow ones. An empirical equation that relates the distortion of thin-wall green-body elements to the blade width and powder layer thickness in the spreading process is proposed. The distortion is shown to be directly proportional to the amount of the powder removed by spreading with the blade and inversely proportional to the added layer thickness. The effect of powder deposition parameters on density distribution in the powder bed is studied. The modeling results are compared with experimental data from binder jetting of green ceramic bodies. All calculations are made with the Bullet Physics SDK open source library to model the deformation of granular media, accounting for friction and energy dissipation in powder particle interactions.