Impact and Deposition of Single and Dual Metal Droplets on Solid Substrate

Abstract

Thermal spraying is a technique within the field of surface treatment processes. It involves the ejection of molten or semi molten droplets onto a prepared substrate, where the droplets deposit successively to produce splats. The accumulation of these splats subsequently forms the coating. Achieving desired coating properties required comprehensive understanding of droplets impact and deposition. Metal droplets deposition on solid surfaces is complex process that combines heat transfer, fluid dynamics and solidification. In order to simulate the dynamics of spreading, deformation and solidification of droplets during the formation of metallic lamella, we developed two-dimensional model in Ansys code. The simulation is conducted by using the volume of fluid method to track the free surface of the impinging droplets. The current study investigates both normal and oblique impact of single and dual aluminum droplets with a diameter of 3.92 mm and an impact velocity of 3 m/s on stainless-steel substrate. The model predicts the morphology of the resulting splat, it was found that the behavior of the dual droplets shows a pattern similar to that of single droplet only with a higher rite of spreading. The simulation results have shown an asymmetric spreading in the oblique impact. Furthermore, the spreading rate of dual droplets is higher than of single droplet in both normal and oblique impact.