Effect of nanodisperse powders on the spreading and crystallization of a metal drop on a porous substrate.

The influence of modifying nanopowders on the spreading and crystallization of a nickel droplet on a porous steel substrate is analyzed. For this purpose, a model has been developed for the spreading of a drop of liquid metal after its high-speed collision with a heated porous substrate. Due to the high impact velocity, the process of metal crystallization is considered after the complete spreading of the drop using the model of heterogeneous nucleation and macroscopic growth of the solid phase, taking into account the size and capillary effects. The influence of the impact velocity and substrate porosity on the thickness and diameter of the formed splat, the penetration depth, and the volume of liquid that penetrated the substrate has been studied. The numerical study of heterogeneous crystallization of a metal drop has made it possible to evaluate the influence of the modifying nanoparticle parameters, the impact velocity, and substrate porosity on the heterogeneous nucleation and on the resulting splat macrostructure.