Deformation and solidification behavior of a molten metal droplet colliding with a substrate: Modeling and experiment

A mathematical model describing the deformation and solidification behavior of a molten metal droplet impinging on cooled substrates was presented. The value of the contact heat transfer coefficient on the droplet/substrate interface was evaluated by comparing the calculated final splat diameter to the experimental one. The evaluated value is within the previously reported ranges. The model almost predicts the dependence of the experimental final splat diameter on the preimpact velocity and the initial droplet diameter. According to the calculation, a thin solid layer is initiated at the spreading front, but it does not fully develop during spreading. The preimpact velocity has little effect on the freezing rate during spreading though it essentially affects the maximum spreading.