DISCRETE ELEMENT METHOD-BASED INVESTIGATION OF HIGH-DENSITY POWDER COMPACTION

Compaction of granular materials plays a critical role in a wide range of industrial applications. Fine powders that entail adhesive, elasto-plastic contacts between particles are particularly relevant in pharmaceutical applications, powder metallurgy and ceramics processing. We present a numerical study that explores macroscopic yield surfaces for high density powder compacts as a function of particle-scale features and compaction conditions. We use the discrete element method (DEM) to simulate a representative number of particles, and reduced-order elastic-plastic-adhesive contact models to capture particle-scale mechanics. Using simulations of arbitrarily complex deformations in periodic geometries, we demonstrate a wide range of three-dimensional yield behaviors that emerge from the interplay of consolidation pressure, friction, adhesion, and plasticity at the particle scale. We also simulate simple geometries that correspond to common characterization experiments, and elucidate the relationships between such experiments and complex yield behavior. This work provides a basis for a multiscale modeling framework of fine powder compaction that connects particle-scale behavior to continuum yield behavior. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.