Numerical analysis of multi-scale mechanical theory of microfine magnesite powder molding

This study presents a discrete element numerical model for the unidirectional compaction of microfine magnesite powder, designed to enhance the green body density based on laboratory apparatus configurations. The research demonstrated that as particle size decreased, porosity significantly reduced and density increased, resulting in a more uniform internal distribution within the green body. This led to closer particle contacts and an increased coordination number, which in turn intensified inter-particle interactions and the effectiveness of force transmission. During compaction, the distribution of force chains became more uniform, reducing localized stress concentrations and enhancing the mechanical integrity of the green body. The stress–strain relationship followed a polynomial pattern, highlighting the significant influence of particle size on the mechanical behavior during compaction. These findings provide a valuable theoretical basis for optimizing the compression molding process of microfine magnesite powder, facilitating the production of high-density, high-performance molded products. Graphical abstract