Three-dimensional granular modeling for metallic powder compaction and flow analysis

Powder is a popular state of material for many industries. In powder metallurgy, it is important to know the behavior of the powder under applied stress to ensure accurate design and good quality. However, the mechanical behaviors of powder is not well understood. The authors consider that this is due in part to the difficulty in handling powder numerically. To investigate the fundamental mechanism of powder behavior, numerical simulation of the behavior of powder under mechanical compression and under applied vibration has been performed. To describe the mechanical behavior of powder in practical forming, granular modeling is a powerful tool. Allowing for the effect of three-dimensionality in the compaction and flowability is essential for precise description of powder behavior. In this paper, three-dimensional granular modeling is proposed and developed for metallic powder compaction and flow analysis. The validity of the method is demonstrated. Formulations based on the three-dimensional direct ball-element method (DBEM-3D) are presented and discussed briefly. In the numerical simulation, static powder compaction and vibration-induced powder behavior considered. The differences between two- and three-dimensional calculations are discussed.