Optimization of the gas system for gas–water combined atomization technique in FeSiBC amorphous powder production

The gas–water combined atomization is an advanced technology for Fe-based amorphous powder preparation, and its gas/water system parameters have significant impacts on powder properties. In this study, numerical simulations and industrial trials were combined to optimize the gas atomization parameters. The results showed that increasing the atomization pressure promotes the transition of the flow field to the closed wake. Moreover, the median particle size was significantly refined and the cooling rate was improved. Extending the extrusion length facilitated the decrease in suction pressure, while excessively long extrusion lengths led to instability in the atomization process. The decrease in delivery tube diameter enhances droplet breakup and cooling, but increases the risk of clogging. Industrial trials at different atomization pressures showed that low atomization pressure led to the formation of needle-shaped powder, and the FeSiBC amorphous powder prepared at 3.0 MPa exhibited optimal comprehensive properties, with saturation magnetization of 166.1 emu·g−1 and coercivity of 4.5 Oe.