https://hdl.handle.net/11256/418 2026-04-08T02:01:31Z https://hdl.handle.net/11115/243 3-Dimensional Reconstructions of Porosity from Laser-Welds of 304L Stainless Steel at 600W and a Variety of Travel Speeds Madison, Jonathan D.; Aagesen, L.K.; Chan, V.W.L.; Thornton, K. Porosity in linear autogenous laser welds of 304 L stainless steel has been investigated using micro-computed tomography to reveal defect content in 54 welds made with varying delivered power, travel speed and focal lens. Trends associated with porosity size and frequencies are shown and interfacial measures are employed to provide quantitative descriptors of pore shape, directionality, interspacing and solid linear fraction. Lastly, the coefficient of variation associated with equivalent pore radii is reported toward a discussion of microstructural variability and the influence of process-parameters on such variability. 2014-04-04T00:00:00Z https://hdl.handle.net/11115/152 3D microstructure reconstruction of polycrystalline nickel micro-tension test Shade, Paul A; Groeber, Michael A; Schuren, Jay C; Uchic, Michael D This article describes a new approach to characterize the deformation response of polycrystalline metals using a combination of novel micro-scale experimental methodologies. An in-situ scanning electron microscope (SEM)-based tension testing system was used to deform micro-scale polycrystalline samples to modest and moderate plastic strains. These tests included measurement of the local displacement field with nm-scale resolution at the sample surface. After testing, focused ion beam serial sectioning experiments that incorporated electron backscatter diffraction mapping were performed to characterize both the internal 3D grain structure and local lattice rotations that developed within the deformed micro-scale test samples. This combination of experiments enables the local surface displacements and internal lattice rotations to be directly correlated with the underlying 3D polycrystalline microstructure, and such information can be used to validate and guide further development of modeling and simulation methods that predict the local plastic deformation response of polycrystalline ensembles. 2013-11-01T00:00:00Z