Process planning guidelines in selective laser melting for the manufacturing of stainless steel parts

Abstract

Selective laser melting (SLM) is now, one of the most widespread Additive Manufacturing processes, due to presence in the market and known capabilities for the fabrication of mechanical components, with acceptable levels in geometrical accuracy, surface quality and mechanical properties. However, the metalworking industry is still skeptical for its full adoption in realistic production schemes, because of the lack of non-scholarly knowledge for calibrating process parameters among other technical barriers. In this work, several process planning guidelines are presented as a result of a SLM process calibration for a selected material (stainless steel 316L), with the intention of contributing in process parameters selection in net shape manufacturing. In order to conceive a proper set of guidelines for selective laser melting set up, several parameters were taken into account such as point distance, hatch distance, exposure time among others, with the aim of obtaining appropriate surface quality and good mechanical tensile behavior. Parts were obtained with good surface quality, presenting stable and well-defined weld lines and low presence of partially sintered particles adhered to the surface. After the application of the methodology, top and lateral surface roughness were improved, reaching values of Ra 5.81 and 9.61 µm respectively. In addition, good mechanical properties were obtained, of up to 500 MPa of ultimate tensile strength and 400 MPa of yield stress, comparable to the properties of sintered stainless steels alloys studied in previous works.