Effects of delivery tube configuration regarding the gas atomization for preparing Fe-based amorphous powders: Numerical and experimental investigation

Abstract

The volume of fluid (VOF) model and the discrete phase model (DPM) were adopted for primary and secondary atomization processes, respectively. The effects of the inlet-limited delivery tube geometry on the flow field, melt breakup and particle cooling were then investigated. The results show that under the delivery tube extrusion length of 5 mm, the suction effect and the breakup efficiency can be improved, and the risk of freeze-off can be inhibited. With the decrease of the delivery tube diameter from 2.5 to 1.5 mm, the calculated median diameter is decreased by more than half and the average cooling rate is more than doubled. The industrial trial results under different delivery tube diameters match the simulation results, and the stable casting of melt with low flow rate can be realized by adopting the inlet-limited delivery tube. When the delivery tube diameter is 1.5 mm, the amorphous powder has a median diameter of 38.9 μm and optimal soft magnetic properties with saturation magnetization of 135.0 emu·g−1 and coercivity of 0.26 Oe.