Anisotropy in impact toughness of powder bed fused AISI 304L stainless steel

The current effort involved investigation into the anisotropy of AISI 304L fabricated through laser powder bed fusion. Charpy V-notch specimens made from material fabricated at three different build orientations were tested and analyzed. A statistically significant difference among the toughness values indicates the presence of anisotropy within the additively manufactured material. While the lowest toughness was found in vertically built specimens, the horizontal specimens were found to exhibit the highest toughness. From the fracture surfaces, an atypical mode of failure was observed. Exclusive crack propagation along the interlayer track boundaries was observed. The toughness variation correlated with the ease of access for crack propagation along the interlayer track boundaries. From Weibull distribution fits of toughness data, the toughness of 3D printed 304L was more variant and lower in comparison with wrought 304L. © 2019 John Wiley & Sons, Ltd.