Effect of solutal Marangoni convection on motion, coarsening, and coalescence of droplets in a monotectic system

In this paper, we study the effect of solutal Marangoni convection (SMC) on the microstructure evolution in a monotectic system, using the convective Cahn-Hilliard and Navier-Stokes equations with a capillary tensor contributed by the chemical concentration gradient. At first, we simulate the spontaneous motion of two distant droplets induced by SMC and compare our results with an analytical solution. We then compute the coalescence of two droplets in contact and coarsening of two distant droplets considering different sizes. We further study the influence of SMC on the evolution of phase separation processes inside the spinodal region for Fe-50 at %Sn and Fe-40 at %Sn alloys. In the former case, we rationalize our results using Fourier spectra and in the latter case, we compare the size distribution of droplets with the LSW theory. DOI: 10.1103/PhysRevE.86.066318