High heating rate sintering and microstructural evolution assessment using the discrete element method

Abstract

An original discrete element model for coupling thermo-mechanics with sintering is presented to disclose the thermo-micromechanical behavior of particulate systems and their densification process under rapid firing. This paper focuses on the numerical model formulation and application on the fast firing of Al2O3, including its verification with literature. Particular emphasis is given to the evolution of thermal and densification gradients over sintering conditions and sample length, zeroing in on the shrinkage evolution and the characteristic densification phenomena. Relationships between defects, microstructure, and sintering parameters are also explored. Finally, the time-dependent change of material microstructure concerning coordination number evolution, cohesive neck size distribution, gradients of temperature, and sample length are analyzed. The numerical results present good agreement with experimental data from the literature.

Keywords

• Rapid sintering
• Discrete element simulation
• Temperature gradient
• Densification
• Micromechanical modeling
• Microstructure evolution