Investigating the Local and Global Tensile Deformation Characteristics of Metallic Specimens Produced by Laser Powder Bed Fusion

Laser powder bed fusion (L-PBF) enables the production of highly customized components with intricate geometries for real-world applications. However, such complexity often introduces notches or stress concentrators that can significantly impact mechanical performance such as tensile properties. As a result, understanding of the tensile behavior of notched L-PBF components is crucial to fully exploiting L-PBF’s potential in structural and load-bearing applications. In this study, notched specimens of Hastelloy X and Ti-6Al-4V are fabricated using L-PBF and subjected to tensile testing at 72 °F and 500 °F. Both local and global tensile properties are examined. The results reveal that local stress values are higher than global stress for both alloys. At elevated temperatures, both alloys exhibit reduced tensile strength and increased elongation. Digital image correlation shows significantstrain localization around the notches at room temperature, with Hastelloy X displaying a more uniform strain distribution compared to the asymmetric pattern observed in Ti-6Al-4V, likely due to rough surfaces near the notch. Hastelloy X also demonstrates significantly higher total elongation, both locally and globally, than Ti-6Al-4V, although it exhibits lower yield and ultimate strength. Microstructural analysis reveals that Hastelloy X specimens have a larger grain size than Ti-6Al-4V, which, in addition to post-processing, notch, and surface finish, potentially contributes to the observed differences in tensile properties.