The kinetics of the liquid–liquid decomposition under the rapid solidification conditions of gas atomization

A model describing the kinetics of the liquid–liquid decomposition under the rapid solidification conditions of gas atomization was developed. The model was satisfactorily verified by comparing with experiments and then applied to investigate the microstructure evolution in the atomized drops of Al–Pb alloy. The numerical results show that the microstructure evolution is the result of the common action of the nucleation, the diffusional growth and the motions of the minority phase droplets. The collision–coagulation of the Pb-rich droplets, which is dominated by droplets’ Stokes movement and Brownian motion under high pressure gas atomization conditions, has an obvious effect on the microstructure development.