Simulation of fast-firing densification by the discrete element method

Abstract

The macroscopic behavior of powder compacts during the sintering process originates at the microscopic level. Despite the marked advance in analytical techniques, the characteristics of microscale densification, including heat transfer phenomena in particulate systems under fast firing, still need to be determined. Here, a numerical approach is used to explore macro and microscale densification gaps aiming to predict the behavior of parts consolidated by non-isothermal sintering. The model was built integrating concepts of heat transfer, transient temperature regime, sintering, and contact forces and implemented within the Discrete Element Method (DEM) framework. The scope of the article includes an alumina-based case study in which simulations were compared with the experimental investigation. The simulation results showed good agreement with the experimental data. Densification microkinetics depicted the evolution of densification gradients inside the sample. The model demonstrated its value for predicting high heating rate sintering features.

Keywords

• Fast Sintering
• Simulation
• Micromechanical modeling
• Thermal-densification gradients