Influence of deposition strategy on porosity in powder-feed directed energy deposition (DED)

Abstract

Abstract. Directed energy deposition (DED) is an additive manufacturing process which is increasingly being used for direct manufacturing, added function application and component repair of high-value metals and alloys that are otherwise hard to machine conventionally [1]. However, most commercially available toolpath generators are not comprehensive with regards to the deposition strategy and process parameters, emphasis usually being placed solely on the overlap of adjacent weld beads rather than including the interaction between the contour curves and infill pattern. This increases the probability of gap formation in the deposition pattern, and hence the rate of porosity in the part. This study focuses on the influence of varying bead overlap on the resulting bead geometry and surface roughness for Inconel 718 workpieces deposited using the DED process. The deposition strategy was devised using Python programming language, and the code found to be robust for both single- and multi-layer deposits.