FEM simulation of splatting of a molten metal droplet in thermal spray coating

In thermal spray coating deposition, the layers of coating are built up by splatting of hot metal droplets onto a cold work piece, flattening of these droplets and ultimately their solidification. The extent of flattening and the pressure evolved during the process are effective on the mechanical properties and bonding strength of the coating layer. In this investigation, the impact of a fully molten metal particle on the surface is simulated using a commercial finite element package, LS-DYNA, in which a 2D axisymmetric domain for deformation is assumed. The equation of momentum is established for the deformed particle in a Lagrangian frame and explicit solution is applied using shell elements. It was revealed that the extent of deformation and the pressure profile evolved during the splatting and changed by variations in stress–strain and pressure–density of material. Null material model for the stress–strain behavior of fully molten metal droplet, and Mie-Gruneisen pressure–density model give reasonable results, particularly for the prediction of the extent of material at the initial time of splatting process. In addition, the particles impacted at a higher velocity are more extended at a shorter time. Null material behavior and Mie-Gruneisen pressure–density relationship represented to be an appropriate material model for fully molten metal droplets impacting at a high speed.