Experimental Investigation of the Overlap Process in Metal Droplet Successive Deposition and Solidification

This paper presents a systematic numerical and experimental investigation of the transient transport phenomenon during the overlap of successive aluminum droplets impinging onto a substrate surface. The 3D models based on a volume of fluid (VOF) method were developed to investigate the successive deposition of molten metal droplets on a horizontally fixed aluminum substrate surface. The numerical models are validated with experiments. The comparisons between numerical simulations and experimental findings show a good agreement. The effects of various parameters such as impact velocities, substrate temperatures and droplet diameters on the maximum spread factor during impacting and spreading with solidification of a molten droplet onto an aluminum substrate surface under different parameters were studied. Based on the above research, the relationships between external morphology and internal microstructure were proposed, which was further certified by investigating the overlap of successive droplets.