Abstract:
A mathematical model is developed for nonequilibrium volume crystallization of a metallic droplet modified by mechanically activated refractory nanoparticles upon its impact onto a solid substrate. The model takes into account the kinetics of heterogeneous and homogeneous nucleation during melt cooling. Specific features of crystallization of a liquid metal (nickel) depending on the concentration and size of modifying particles are examined numerically. A typical feature of the process considered is the maximum supercooling of the melt, whose magnitude depends on the particle size and cooling intensity. Homogeneous nucleation is almost absent. The calculated radii of droplets solidified on the substrate are in good agreement with available experimental data.