3D-printed metals: Process parameters effects on mechanical properties of 17-4 P H stainless steel

: Additive Manufacturing (AM) has spread significantly in recent years, with relevant applications in many fields of research and engineering. Thanks to its distinctive production methods, AM enables the creation of parts with complex shapes that cannot be fabricated easily by employing traditional subtractive processes. 3D printing, which involves overlapping material layer by layer until the designed part is completed, shows several advantages in terms of limiting material waste, reducing production phases and postprocessing/heat treatments needs, leading to an additional benefit in terms of environmental sustainability. However, there are still limited available data on the influence of the 3D printing process on the mechanical properties of the materials that are commonly used and additional investigations are strongly demanded. So, the purpose of the present paper is to provide a useful contribution in the field of metal additive manufacturing, reporting the results of an experimental campaign carried out on 17-4 P H stainless steel, produced using selective laser melting technology. The effects of different printing orientations and scanning times on the tensile behaviour, impact strength and microhardness features of the 3D-printed products are investigated. Furthermore, the influence of an annealing heat treatment on the material mechanical performance is evaluated.