A novel selection method of slice thickness in metal micro-droplet deposition manufacture

In order to fabricate precise metal components by sequentially depositing molten metal droplets on substrate layer by layer, the perfect slice thickness of part model have to be obtained. In this paper, the influence of deposited layer thickness of droplets was investigated, and the deposited layer thickness was calculated by analyzing the relationship of the shape parameters of solidified droplet on the substrate. A simple and effective model was proposed to calculate and predict the slice thickness (Hs). The calculation results show that the Hs was only affected by droplet diameter (D) and solidification angle (θ). Based on this analysis, a thin-walled tube was fabricated with different slice thicknesses (263 μm, 306 μm, 320 μm,365 μm and 400 μm) on the condition of fixed droplet diameter (400 μm)and Solidification angle (121.5°), which indicate that the calculation method i is effective and feasible. On this basis, a complex micro honeycomb structure (4 mm in deposition direction), which was deposited by the 312 μm diameter droplets and the 87.5° solidification angle. The high dimensional accuracy (the relative error is 1.5-3.75%) has been obtained in deposition direction with the calculated slice thickness (Hs = 192 μm) according to calculated models. The work provides an effective method for optimizing slice thickness and improving the dimensional accuracy of the formed components by droplet-based freeform fabrication.