Numerical simulation and experimental research on fused-coating additive manufacturing of Sn63Pb37 thin-walled structures

摘要

Metal fused-coating additive manufacturing of Sn63Pb37 with single-track two-layer was performed. A 3D thermal FVM model has been developed to calculate the temperature field and solidification morphology of deposited layers. Results of numerical calculation, experimental of the micrographs and morphologies were presented, discussed and checked. The influences of the melt temperature and substrate temperature on the re-melted depth were analyzed. Physical values such as the ratio of overlap width and surface waviness were selected as indicators for the interlayer bond strength and macroscopic surface quality of copper deposits. The results suggest that when the temperatures of melt and substrate are 200 degrees C and 60 degrees C, respectively, the re-melted depth is close to zero because the heat from the liquid metal is still not hot enough to melt the surface of the previously deposited layers. As the temperature of melt and substrate increases, the re-melted depth reaches 0.5 mm or more, the collapse of previous deposited layers may occur due to the increased heat and the build-up of mass during deposition. A range of re-melted depth 0.2-0.5 mm is optimal for surface roughness and bonding strength of deposited layers. Moreover, the surface waviness was characterized by the difference of the maximum crest and minimum trough. When the temperatures of melt and substrate are 260 degrees C and 110 degrees C, respectively, and layer thickness 1.2 mm, surface waviness has the maximal value of 0.23 mm.