Abstract

Particle breakage during compaction affects compaction behavior and the quality of the formed compact. This work conducted a numerical study based on the discrete element method (DEM) to investigate the effect of particle breakage on compaction dynamics and compact properties, including particle size and density distributions, and pore properties. A force-based breakage criterion and Apollonian sphere packing algorithm were employed to characterize particle breakage behavior. The pore structures of the compacts were characterized by the watershed pore segmentation method. Calibrated with experimental data, the model was able to simulate the stress-strain relation comparable with experimental observation. During compaction, the particles were gradually broken from top to bottom with increasing pressure. Both density and pore size of the compacts had relatively uniform distribution at larger stress, while the pore size decreased sharply when the particles started to break, indicating that the smaller fragments in the compact system have a significant effect on the pore size distribution.

Highlights

  • Compaction of powders is widely used in fields such as pharmaceutical tableting, soil consolidation, mineral processing, and powder metallurgy [1]

  • Previous experimental studies on particle breakage in compaction were mainly focused on individual particle breakage patterns and the effects of initial density and particle size distribution (PSD) on particle breakage [3,4]

  • Sensitivity tests were conducted to investigate the effect of the number of fragments replacing the original particles on the compaction curve and final PSD. 8, 20, and 57 spheres, corresponding to generation 1, 2, and 3 of the Apollonian packing (see inset of Fig. 1(a)), were adopted in the simulations

Read more

Summary

Introduction

Compaction of powders is widely used in fields such as pharmaceutical tableting, soil consolidation, mineral processing, and powder metallurgy [1]. Particles may experience breakage, which affects compaction behavior and the structural and mechanical properties of formed compacts [2]. Previous experimental studies on particle breakage in compaction were mainly focused on individual particle breakage patterns and the effects of initial density and particle size distribution (PSD) on particle breakage [3,4]. Their results showed that the compaction curve and breakage pattern depended on the loading and initial PSD. Studies on the effect of particle breakage on compact structures during the compaction process are still limited. A force-based breakage model was implemented in the DEM model, and an image-based algorithm was adopted to analyze pore structures in a

DEM model
Simulation conditions
Pore structure analysis
Sensitivity test and model validation
Evolutions of compacts
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call