15 research outputs found
Porosity detection in electron beam-melted Ti-6Al-4V using high-resolution neutron imaging and grating-based interferometry
© 2017, Springer International Publishing Switzerland. A high-resolution neutron tomography system and a grating-based interferometer are used to explore electron beam-melted titanium test objects. The high-resolution neutron tomography system (attenuation-based imaging) has a pixel size of 6.4 µm, appropriate for detecting voids near 25 µm over a (1.5 cm)3 volume. The neutron interferometer provides dark-field (small-angle scattering) images with a pixel size of 30 µm. Moreover, the interferometer can be tuned to a scattering length, in this case, 1.97 µm, with a field-of-view of (6 cm)3. The combination of high-resolution imaging with grating-based interferometry provides a way for nondestructive testing of defective titanium samples. A chimney-like pore structure was discovered in the attenuation and dark-field images along one face of an electron beam-melted (EBM) Ti-6Al-4V cube. Tomographic reconstructions of the titanium samples are utilized as a source for a binary volume and for skeletonization of the pores. The dark-field volume shows features with dimensions near and smaller than the interferometer auto-correlation scattering length
Application of Wear-Resistant, NanoComposite Coatings Produced from Iron-Based Glassy Powders
This report talks about Application of Wear-Resistant, NanoComposite Coatings Produced from Iron-Based Glassy Powders
Spinodal-assisted crystallization in polymer melts
Recent experiments in some polymer melts quenched below the melting temperature have reported spinodal kinetics in small-angle x-ray scattering before the emergence of a crystalline structure. To explain these observations we propose that the coupling between density and chain conformation induces a liquid-liquid binodal within the equilibrium liquid-crystalline solid coexistence region. A simple phenomenological theory is developed to illustrate this idea, and several experimentally testable consequences are discussed. Shear is shown to enhance the kinetic role of the hidden binodal
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Near Net Shape Manufacturing of New, Low Cost Titanium Powders for Industry
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Application of Wear-Resistant, NanoComposite Coatings Produced from Iron-Based Glassy Powders, 2013, April 08
This report talks about Application of Wear-Resistant, NanoComposite Coatings Produced from Iron-Based Glassy Powders