The growth of particles in an alloy melt with Soret diffusion

•The growth of the particle in the alloy melt with the Soret diffusion is studied.•The approximately analytical solution is obtained by the asymptotic method.•The Soret diffusion markedly modifies the solute concentration distribution.•The Soret diffusion shows an amplification effect of growth velocity of the particle. The growth of particles in an alloy melt with the thermodiffusion is studied by using the asymptotic method. The resulting asymptotic solution for the dynamic model of the particle reveals that depending on the sign of the Soret coefficient, the solute concentration distribution is markedly modified and the growth velocity of the particle is increased or decreased. When the Soret coefficient is positive, as the growth velocity of the particle decreases, the thermodiffusion accelerates the decay of the particle, whereas as the growth velocity of the particle increases, the thermodiffusion accelerates the growth of the particle. As a result, the thermodiffusion presents an amplification effect of the growth velocity of the particle, being more significant in the early growth stage of the particle after nucleation. However, when the Soret coefficient is negative, as the growth velocity of the particle decreases, the thermodiffusion depresses the decay of the particle; as the growth velocity of the particle increases, the thermodiffusion depresses the growth of the particle. The thermodiffusion presents a reduction effect of the growth velocity of the particle accordingly.