A Comparison of the Laser Powder Interaction in Laser Powder Bed Fusion and Direct Energy Deposition Processes

Metal additive manufacturing (AM) is a class of innovative production technologies that allows the production of metal components layer by layer directly from a Computer Aided Design (CAD) model. The AM process of aluminium and aluminium alloys gained much interest in past years especially thanks to the high geometrical freedom, the peculiar microstructures and enhanced mechanical properties it is possible to achieve. However, the quality of final metal components strongly depends on the stability and the quality of each single scan track. Therefore, the understanding of the laser-powder interaction and of the phenomena that arise in the melt pool is a key aspect for the development of these technologies. In this work, AlSi10Mg single scan tracks (SSTs), produced by laser powder bed fusion (LPBF) and direct energy deposition (DED), were analysed and compared in order to select the most suitable range of parameters for each building process.