Comparison of the porosity and mechanical performance of 316L stainless steel manufactured on different laser powder bed fusion metal additive manufacturing machines

Abstract

Despite the recent progress in additive manufacturing (AM) process and technology, challenges in the repeatability and reproducibility of AM parts still hinders the adoption of this technique in many industries. This is particularly difficult when a part is qualified on a particular part on a certain machine using optimised parameters. If a manufacturer wishes to expand production to multiple machines, the ability to translate these optimised parameters to different machines much be understood. In this study, four different metal L-PBF printers were used to produce 316L tensile testing samples using the same processing parameters and metal powder supplied from a single batch from the same supplier. In addition to the analysis of the correlation between the input parameters and the output measures, this study reports that despite the same set process parameters, there is significant variations were found in the mechanical performance and properties of the AM samples produced on the different L-PBF metal additive manufacturing machines. For the range of the input processing parameters and the resulting input volumetric energy density applied of 21–37 J/mm3, values of (4–42)%, (200–716) MPa, and (52–214) GPa were obtained for the elongation, ultimate tensile strength and elastic modulus on additively manufactured 316L samples respectively.

Keywords

• Additive manufacturing
• Laser powder bed fusion (L-PBF)
• Selective laser melting (SLM)
• 3D printing
• Optimisation
• Tensile testing