Simulation of sintering using a Non Smooth Discrete Element Method. Application to the study of rearrangement

The effective shear and bulk viscosity, as well as dynamic viscosity, describe the rheological properties of the ceramic body during the liquid phase sintering process. The rheological parameters depend on the physical and thermo‐mechanical characteristics of the material such as relative density, temperature, grain size, diffusion coefficient, and activation energy. In this paper, the numerical‐experimental method has been developed to study both viscous and rheological behavior of hard porcelain ceramic body during liquid phase sintering. The other aim is to acquire a complete understanding of the response of an incompressible viscose material during sintering such as stress‐strain relations, sintering, and hydrostatic stress. Densification results confirmed that the bulk viscosity was well‐defined with relative density. The stress analysis proved that the sintering stress is more than the hydrostatic stress during the entire sintering time so, the sintering process occurs completely. Deflection results showed that the shear viscosity was a fair estimation of real ones. Dilatometry, SEM, XRD investigations as well as bulk viscosity simulation results confirmed that the “mullitisation plateau” was presented as a very little extraordinary expansion at the final sintering stage.

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“…The pyroplasticity index ( PI ) values and apparent material viscosity (η) were calculated according to Equation and , respectively .

P I = \frac{δ h^{2}}{L^{4}}

η = \frac{5 {normalρ}_{normalb} g L^{4}}{32 \dot{normalδ} h^{2}}

…”

Section: Methodsmentioning

confidence: 99%

Evaluation of dynamic viscosity and rheological properties of ceramic materials during liquid phase sintering by numerical‐experimental procedure

Nasrabadi

Salahi

Asil

2017

Int J Applied Ceramic Tech

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“…The DEM simulations have been used to simulate the mill process [10,11], powder mixing [12,13], or powder packing [14][15][16][17][18][19][20][21][22][23][24]. Moreover, some approaches have been developed over the last years to simulate the behavior of the particles during the heat treatment in the sintering process [25][26][27][28][29]. In these works, the authors incorporated the concepts of the model developed by Parhami et al [30] into three-dimensional (3D) DEM models.…”

Section: Introductionmentioning

confidence: 99%

Numerical Modeling for Simulation of Compaction of Refractory Materials for Secondary Steelmaking

et al. 2020

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The purpose of this work is to simulate the powder compaction of refractory materials, using the discrete element method (DEM). The capability of two cohesive contact models, implemented in different DEM packages, to simulate the compaction of a mixture of two refractory materials (dead burnt magnesia (MgO) and calcined alumina (Al2O3)) was analyzed, and the simulation results were compared with experimental data. The maximum force applied by the punch and the porosity and final shape quality of the compact were examined. As a starting point, the influence of Young’s modulus (E), the cohesion energy density (CED), and the diameter of the Al2O3 particles (D) on the results was analyzed. This analysis allowed to distinguish that E and CED were the most influential factors. Therefore, a more extensive examination of these two factors was performed afterward, using a fixed value of D. The analysis of the combined effect of these factors made it possible to calibrate the DEM models, and consequently, after this calibration, the compacts had an adequate final shape quality and the maximum force applied in the simulations matched with the experimental one. However, the porosity of the simulated compacts was higher than that of the real ones. To reduce the porosity of the compacts, lower values of D were also modeled. Consequently, the relative deviation of the porosity was reduced from 40–50% to 20%, using a value of D equal to 0.15 mm.

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“…The DEM simulations were run using an original implicit approach based on Non Smooth Contact Dynamics [8] that allows the avoidance of mass scaling. The authors showed in previous study that this method leads to a better representation of rearrangement during sintering [9].…”

Section: Introductionmentioning

confidence: 99%

Validation of DEM modeling of sintering using an in situ X-ray microtomography analysis of the sintering of NaCl powder

et al. 2015

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This paper aims to validate the Discrete Element Method (DEM) model of sintering. In situ X-ray microtomography experiments have been carried out at the ESRF to follow the sintering of N aCl powder, the properties of which are close to the DEM model assumptions. DEM simulations are then run using an improved implicit method. The comparison between experiment and simulation shows the capability of DEM to predict the behavior of the sample on both particle and packing scale. The main advantages and limits of this approach are finally discussed based on these results and those of previous studies.

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Simulation of sintering using a Non Smooth Discrete Element Method. Application to the study of rearrangement

Cited by 32 publications

References 35 publications

Evaluation of dynamic viscosity and rheological properties of ceramic materials during liquid phase sintering by numerical‐experimental procedure

Evaluation of dynamic viscosity and rheological properties of ceramic materials during liquid phase sintering by numerical‐experimental procedure

Numerical Modeling for Simulation of Compaction of Refractory Materials for Secondary Steelmaking

Validation of DEM modeling of sintering using an in situ X-ray microtomography analysis of the sintering of NaCl powder

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