Molecular Dynamics Simulation of Flattening Process of a High-Temperature, High-Speed Droplet—Influence of Impact Parameters

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. In this report, the influence of the impact parameters such as the droplet velocity and the droplet diameter on flattening behavior were analyzed. As a result, the following representative conclusions were obtained: (a) the flattening ratio increases in proportion to the droplet velocity and the droplet diameter; (b) the flattening ratio for nanosized droplet can be reorganized by the same dimensionless parameters of the proper physical properties, such as the viscosity and the surface tension, as those used in the macroscopic flattening process. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.