Atomization process of GH4099 superalloy powder prepared by dual-gas nozzle

GH4099 is a typical age-hardened nickel-based superalloy with excellent overall performance, widely used in aerospace and other fields. In this study, a novel tight-coupled dual-gas nozzle is designed, and a two-phase coupling breakup model for the atomization process is established based on the volume of fluid flow model. The breakup behavior of the melt under high-speed gas flow is investigated in depth. The generation of melt droplets is analyzed, in the atomization process of this nozzle, the melt enters the atomization chamber and is first impacted by the intermediate airflow to generate the initial droplets, and the initial droplets move toward the outer air flow channel under the action of the air flow and continue to break into smaller droplets under the action of the outer air flow channel. Powder particles are sampled at the nozzle exit, and the particle characteristics generated by atomization are analyzed in detail. The final particle size distribution is obtained, and the influence of gas pressure and gas injection angle on the particle size distribution are explored. The results show that, within the studied parameter range, as the gas pressure increases, the powder particle size first increases and then decreases. As the gas injection angle decreases, the powder particle size also decreases, so a small injection angle is favorable to the powder particle size reduction. When the gas pressure P2 = 4.5 MPa, the injection angle α = 25°, The powder has the narrowest particle size distribution, and the particle size is smaller, the median diameter of the particles D50 = 29.1 μm. The findings of this study provide important references for the nozzle structure design and process parameter optimization for high-temperature alloys.