Recent Developments in the Research of Splat Formation Process in Thermal Spraying
Figure 6
Substrate melting-induced splashing model [23]. indicates the flow direction of the spreading fluid driven by kinetic energy. is the heat transfer direction from the droplet to the substrate. (a) and (b) indicate the early stages of flattening, resulting in the melting of the substrate by the impacting droplet. indicates the flow direction of the spreading fluid resulting from the crater, which is formed by the melted substrate surface region. indicates the direction of the evaporated gas-induced force. When flattening completes (c), the splashing occurs, driven by the inertial force of the rapidly flowing fluid along direction . Cracking occurs as the surface layer of the splat is solidified, as shown in (c) and (d). The displacement by floating of the cracked splits on low-melting-point liquid film results in the formation of splitting of the residual central splat (e) and the final splat (f).
