Thermal Effects on the Spreading and Solidification of a Micrometric Molten Particle Impacting onto a Rigid Substrate

The splat formation is one of the basic processes in thermal spray coatings. The performance of these coatings is strongly related to the process of spreading and solidification of molten droplets. The aim of the present paper is to simulate the fluid flow, heat transfer and phase-change that occur when a micrometric molten droplet impacts onto a rigid substrate and to examine the effect of the substrate conditions, such as initial temperature and material on the solidification time and spreading process. The effect of thermal contact resistance is also investigated. The simulation model used is based on the Navier-Stokes equations and the energy equation which includes convection and phase change. These equations are coupled with the Level Set function to track the interface between molten particle and surrounding air. The numerical model is solved using Finite Element Method and Comsol multiphysics 3.5a software.