Mechanical properties of 316L stainless steel samples fabricated by selective laser melting and comparison with other manufacturing methods

Abstract

Selective laser melting (SLM) is an additive manufacturing technique in which a laser beam with a high energy density is used to melt a metal powder substrate. Although this technique has several advantages, including the possibility of fabricating complex metal components quickly, there are concerns about the mechanical properties of the parts produced by the SLM method. This is study aims to ensure the achievement of acceptable mechanical properties including yield stress, tensile strength, and elongation percentage compared to conventional manufacturing methods. For this purpose, samples of 316L stainless steel were printed using the SLM machine. These samples and samples of annealed 316L bar were tested under same conditions and by the same equipment. Despite the large differences in microscopic structure, no significant differences were observed in mechanical properties. Also, the obtained results were compared with the results related to the sample made by the DLD additive manufacturing method, which is similar to SLM in terms of energy source and raw materials. The result represents that the mechanical strength and microhardness of the sample produced by the SLM technique are higher than the other samples, and the elongation percentage is within the desirable range. The yield stress, tensile strength, and elongation are respectively 595Mpa, 696Mpa, and 34.5%, all of which are within the acceptable range required by the standards for such samples. The investigation of the microstructure shows a complete austenitic cellular structure without considerable solidification defects. Overall, the SLM additive manufacturing is a reliable process to produce 316L stainless steel parts in terms of mechanical properties.