Effect of cohesion on the gravity-driven evacuation of metal powder through Triply-Periodic Minimal Surface structures

TL;DR

This study uses simulations to analyze how cohesion affects gravity-driven evacuation of metal powder in TPMS structures, identifying topologies that optimize de-powdering efficiency in additive manufacturing.

Contribution

It introduces a systematic simulation approach to evaluate the impact of cohesion on powder evacuation in different TPMS topologies, highlighting the Schwarz-P and Gyroid structures as most effective.

Findings

Schwarz-P and Gyroid topologies facilitate efficient powder evacuation.

Cohesion significantly influences discharge profiles and flow hindrance.

Detailed kinematic analysis reveals particle contact force distributions.

Abstract

Evacuating the powder trapped inside the complex cavities of Triply Periodic Minimal Surface (TPMS) structures remains a major challenge in metal-powder-based additive manufacturing. The Discrete Element Method offers valuable insights into this evacuation process, enabling the design of effective de-powdering strategies. In this study, we simulate gravity-driven evacuation of trapped powders from inside unit cells of various TPMS structures. We systematically investigate the role of cohesive energy density in shaping the discharge profile. Overall, we conclude that the Schwarz-P and Gyroid topologies enable the most efficient powder evacuation, remaining resilient to cohesion-induced flow hindrance. Furthermore, for the two unit cells, we analyse detailed kinematics and interpret the results in relation to particle overlaps and contact force distributions.