Experiment characterization and formulation estimation of tensile properties for selective laser melting manufactured 304L stainless steel

Additive manufacturing (AM) becomes more and more prevalent and offers enormous benefits on account of its inherent layer-by-layer nature. Material characterizations of such printed metal alloy are essential and necessary to understand the unique process-properties maps of different structures. From which, the tensile performance is one of the most demanding and concerning behaviors by diverse requirements from industries. In this study, experimental methodologies (uniaxial tensile testing and automated ball indentation testing) and constitutive relations (Holloman, Swift, Voce, and Ludwigson formulation) studies were performed to AISI 304L stainless steel. A comparative study was presented between selective laser melting fabricated parts and conventional counterparts. Outputs indicated the Swift formulations provided the best estimations of the flow curve. All four formulations provided reasonable estimations of ultimate tensile strength. Anisotropic study in tensile strength and work hardening exponent with varying build orientations were correlated to grain structures. The non-destructive automated ball indentation test yielded the acceptable tensile strength with the accurate determination of plastic chordal diameter. However, the automated ball indentation test demonstrated an insensitive manner on the anisotropy.