The effect of internal defects on tensile tests of additively manufactured metal samples: In-situ tensile testing during X-ray computed tomography
Felix Kim, Shawn P. Moylan, Thien Q. Phan, Edward Garboczi
Tensile mechanical tests were carried out simultaneously with high-resolution X-ray computed tomography (XCT) measurements on 17-4 stainless steel tensile dog-bone samples with a built octahedron-shaped internal feature embedded in the gauge length and also containing natural, much smaller, lack-of-fusion (LOF) defects, all generated by a Laser Powder Bed Fusion (LPBF) Additive Manufacturing process. The LOF defects were introduced by intentionally changing the LPBF default processing parameters. The in-situ mechanical tests combined with simultaneous XCT measurements revealed the details of the failure process initiated by additively manufactured rough internal surfaces and porous defect structures, which experienced high stress concentration. The high stress concentration was also directly confirmed from XCT image-based linear elastic finite element (FE) simulations. We demonstrate that the experimental methods described in this paper are promising methods to study complex failure mechanisms of additively manufactured parts, and the image- based FE simulation method is a promising predictive simulation tool to identify and/or confirm possible failure locations and features.
, Moylan, S.
, Phan, T.
and Garboczi, E.
The effect of internal defects on tensile tests of additively manufactured metal samples: In-situ tensile testing during X-ray computed tomography, Experimental Mechanics, [online], https://doi.org/10.1007/s11340-020-00604-6, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=927868
(Accessed November 30, 2021)