Compression properties of bimodal powders with different plasticities in the elastoplastic powder compression process: A numerical analysis

Abstract

Powder compression has been utilized in various industries, including pharmaceuticals, foods, metals, and batteries. Although powder properties affect the compact structure, these effects remain unclear. In this study, we used the discrete element method to investigate the effects of particle cohesiveness and plasticity on the compression of bimodal powders. The Edinburgh elastoplastic adhesion model, which considers particle cohesiveness and plastic deformation, was applied as the contact model. The particle plasticity λp was varied from 0 to 0.7. The macroscopic and microscopic properties of the powder compression were investigated. The void fractions of two-component powder mixtures with different plasticities were evaluated. In contrast to that for the elastic model, the void fraction at Vf = 0.5 was smaller than that at Vf = 0.3 for the high plastic condition (λp = 0.7). In addition, as the number of fine particles increased, the largest contact type changed in the order of coarse–coarse, coarse–fine, and fine–fine. The plasticity of the particles enhanced the effects of fine particle addition. This study suggests that it is essential to determine the optimal addition ratio of fine particles based on the plastic deformability of the material.