The quality of 3D printing parts obtained by means of droplets deposition depends strongly on the mechanism of the interaction between the molten metal droplets and the substrate to be covered. The effects of various parameters such as impact velocity, substrate temperature, droplet diameters, specific heat, thermal conductivity, latent heat on the maximum spread factor during impacting and spreading with solidification of a molten droplet onto an aluminum surface under different parameters was studied. The free surface of the droplet was tracked by the volume-of-fluid (VOF) method. The simulation model was based on the N-S equations and the energy equations which include convection and phase change. These equations were coupled with the Level Set function to track the interface between molten particles and surrounding air. The maximum spread factors were obtained and were in agreement with the experimental data available in the literature.