Dresden 2017 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 31: Particulate Matter I: From microscopic interactions to collective motion (Focus session)

DY 31.11: Talk

Wednesday, March 22, 2017, 12:45–13:00, ZEU 118

Particle-based model for the coating of complex-shaped, cohesive powder particles in additive manufacturing — •Eric Parteli¹ and Thorsten Pöschel² — ¹University of Cologne — ²Friedrich-Alexander-University of Erlangen-Nuremberg

The development of reliable strategies to optimize part production in additive manufacturing technologies hinges, to a large extent, on the quantitative understanding of the mechanical behavior of the powder particles during the application process. In the present work, we develop a numerical tool for the particle-based simulations of powder application in additive manufacturing devices. Our simulations take into account an accurate description for the attractive particle interaction forces as well as the complex geometric shapes of the applied powder particles. To verify our numerical tool, we compute packing density of polydisperse powder systems of different materials, covering a broad range of size distributions, thereby finding excellent quantitative agreement with measurements. From simulations of powder coating in additive manufacturing, we find that the mechanical behavior of the bulk is fundamentally influenced by the dynamics of the powder at the microscopic level, in particular the formation of complex-shaped particle agglomerates and the concatenated suppression of pore filling by smallest particles in the distribution. We show that this behavior is responsible for one surprising result, namely that broader size distributions lead to coated powder beds of lower solid fractions. Moreover, an increase in surface roughness of the powder bed with process speed is found, thus suggesting decrease in part quality with production speed.