A scaling up of flattening silver particles using dry ball milling by DEM simulation

The rising demand for silver flakes, such as those used on solar cell electrodes, requires reliable scaling up of flattening silver particles. For this purpose, it was confirmed the applicability of the specific impact energy ($${E}_{w}$$) calculated from the discrete element method (DEM) simulation to the scale-up of flattening silver particles. The normalized specific surface area (SSA) at arbitrary flattening times at large scales was predicted by the flattening rate constant ($${K}_{f}$$) at small scales and $${E}_{w}$$. Silver particles were flattened in experiments using dry vibration mills of two different sizes under various conditions. $${K}_{f}$$ was obtained through the increase in the normalized SSA during the flattening process. The simulations modeled the motion of the balls within the mills using DEM, and $${E}_{w}$$ was calculated from the ball-ball and ball-wall collisions. To validate the scale-up, the predicted and experimental values of the normalized SSA at large scales were compared. A comparative analysis of prediction accuracy using various components of $${E}_{w}$$ (normal, shear, and their total) was conducted. The results showed that the normal component of $${E}_{w}$$ had the highest prediction accuracy. These findings suggest that the normal component of $${E}_{w}$$ can be utilized to the scale-up of flattening processes.