Study of the influence of laser energy density on the surface roughness of Scalmalloy^® samples manufactured by DMLS technology

Direct Metal Laser Sintering (DMLS) is an additive metal manufacturing technology that allows complex parts to be built without the design constraints of conventional technologies. In addition, the possibility of reusing powder reduces raw material consumption and the amount of waste generated. However, one of the disadvantages of this technology is that, in most cases, it requires post-processing tasks that increase manufacturing costs and delivery times. Some of these additional tasks are aimed at reducing the surface roughness of the parts obtained, using technologies such as grinding, mechanical polishing, shot blasting or electropolishing. This work proposes to improve the surface quality of parts manufactured by DMLS by controlling the processing parameters. In this way, the costs associated with these post-processing tasks could be reduced. Specifically, it is proposed to study the effect of the laser energy density applied to the surface of the parts during the manufacturing process on their surface quality. To carry out this study, powders of the Al-Mg-Sc alloy known as Scalmalloy^®, developed to manufacture parts by means of DMLS with application in the aeronautical sector, have been used. In this sector, surface quality is one of the factors limiting the implementation of DMLS technology for the manufacture of parts considered critical.