Electron backscatter diffraction

About: Electron backscatter diffraction is a research topic. Over the lifetime, 15184 publications have been published within this topic receiving 317847 citations. The topic is also known as: EBSD.

Crystallography of Zirconium Hydrides in Recrystallized Zircaloy-2 Fuel Cladding by Electron Backscatter Diffraction

Abstract: Precipitation morphology and habit planes of the delta-phase Zr hydrides, which were precipitated within the a-phase matrix grains and along the grain boundaries of recrystallized Zircaloy-2 cladding tube, have been examined by electron backscatter diffraction (EBSD). Radially-oriented hydrides, induced by residual tensile stress, precipitated in the outside region of the cladding, and circumferentially-oriented hydrides in the stress-free middle region of the cladding. The most common crystallographic relationship for both types of the hydrides precipitated at the inter- and intra-granular sites was identical at (0001)(alpha) // {111}(delta), with {1017}(alpha) // {111}(delta) being the occasional exception only for the inter-granular radial hydrides. When tensile stress was loaded, the intra-granular hydrides tended to preferentially precipitate in the grains with circumferential basal pole textures. The inter-granular hydrides tended to preferentially precipitate on the grain faces opposite to tensile axis. The change of prioritization in the precipitation sites for the hydrides due to tensile stress could be explained in terms of the relaxation effect of constrained elastic energy on the terminal solid solubility of hydrogen at hydride precipitation.

Influence of texture and grain refinement on the mechanical behavior of AA2219 fabricated by high shear solid state material deposition

Abstract: Issues with rapid grain growth, hot cracking and poor ductility have hindered the additive manufacturing and repair of aluminum alloys. Therefore, this is the first investigation to spatially correlate the processing-structure-property relations of a precipitation hardened aluminum alloy 2219 (AA2219) material with respect to deposition orientations and build layers. The AA2219 material was processed by a high deposition rate (1000 cm3/h) solid-state additive deposition process known as Additive Friction Stir Deposition or MELD. An equiaxed grain morphology was observed in the three orientations, where Electron Backscatter Diffraction (EBSD) identified a layer-dependent texture with a strong torsional fiber A texture in the top of the build transitioning to weaker textures in the middle and bottom layers. Interestingly, the tensile behavior reflected the texture layer-dependence with tensile strength increasing from the bottom to the top of the deposition. However, there were no statistically significant differences in hardness measured from the top to the bottom of the deposition. Furthermore, no orientation dependence on mechanical properties was observed for compression and tension specimens tested at quasi-static (0.001/s) and high (1500/s) strain rate. Transmission Electron Microscopy (TEM) determined a lack of θ′ precipitates in the as-deposited cross-section, therefore resulting in no precipitation strengthening.