Molecular Dynamics Analysis of Elementary Process of Coating by a High-Temperature, High-Speed Droplet

Three-dimensional molecular dynamics simulation was conducted to clarify at an atomic level the flattening process of a high-temperature droplet impacting a substrate at high speed. The droplet and the substrate were assumed to consist of pure aluminum, and the Morse potential was postulated between a pair of aluminum atoms. By visualizing the analytical results, the processes of melting and solidification, temperature distribution, deformation velocity, and potential energy of atoms of the droplet were clarified. The following conclusions were obtained: (1) Transfer of the droplet atoms to the horizontal direction in the flattening process increases in proportion to the horizontal distance from the central axis of the droplet. (2) The increase of the flattening ratio of the droplet ends as soon as solidification of the droplet starts from the outside edge of the droplet. This behavior indicates the end of flattening.