Numerical Study on Substrate Remelting, Flow, and Resolidification in Microcasting Available to Purchase

A large and highly superheated molten droplet impacting onto the substrate during the microcasting was studied numerically. In this study, same material for both the droplet and the substrate was considered. Numerical model including the complex fluid dynamics of droplet, interfacial thermal contact resistance, and substrate remelting, as well as the flow in the substrate has been developed. Numerical simulations of a microcasting experiment were conducted with the different thermal contact resistances. The results of simulations show that the spreading factor and substrate remelting agreed well with the experimental data under the assumption of an appropriate thermal contact resistance. It is also found that the thermal contact resistance plays an important role not only in droplet spreading arrest but also in the determination of substrate remelting volume and remelting front shape. The effects of droplet impacting velocity, superheat and substrate temperature were also investigated.