In situ strain profiling of elastoplastic bending in Ti–6Al–4V alloy by synchrotron energy dispersive x-ray diffraction

Abstract

Elastic and plastic strain evolution under four-point bending has been studied by synchrotron energy dispersive x-ray diffraction. Measured strain profiles across the specimen thickness showed an increasing linear elastic strain gradient under increasing four-point bending load up to ϳ2 kN. The bulk elastic modulus of Ti-6Al-4V was determined as 118 GPa. The onset of plastic deformation was found to set in at a total in-plane strain of ϳ0.008, both under tension and compression. Plastic deformation under bending is initiated in the vicinity of the surface and at a stress of 1100 MPa, and propagates inward, while a finite core region remains elastically deformed up to 3.67 kN loading. The onset of the plastic regime and the plastic regime itself has been verified by monitoring the line broadening of the ͑100͒ peak of ␣-Ti. The effective compression/tension stress-strain curve has been obtained from the scaling collapse of strain profile data taken at seven external load levels. A similar multiple load scaling collapse of the plastic strain variation has also been obtained. The level of precision in strain measurement reported herein was evaluated and found to be 1.5ϫ 10 −5 or better.

Energy Dispersive X-ray Diffraction Profiling of Prototype LiMn2O4-Based Coin Cells

“…Schematic transmission diffraction geometry and incident/scattered beam collimation slits can be found in the references of this paper. 5,7,8,10 A schematic of the experimental geometry in these coin cell experiments is shown in Figure 2. In the conventional units, where d hkl is measured in Angstroms and E in keV, one has b = 6.199 Å keV.…”

Fast Neutron Irradiation Embrittlement-ductilitization of an Iron-based Amorphous Alloy using In Situ Synchrotron X-ray Diffraction

“…Here, the total length of the sample is 42 mm, the gauge length (central section) is 6 mm long, and the width is 1.5 mm, giving a total thickness of 1.4 mm (steel substrate) + 240 μm (amorphous Fe-based coating). The simulations were used as a guide in the ensuing in situ X-ray analysis of d-spacing shifts from which strains were assessed, and the stresses were computes (see [20]).…”

“…the solid amorphous [15]. However, based on analysis of the EDS spectra and X-ray diffraction patterns of the amorphous coating, it is assessed that the thermal sprayed amor-X17-B1 can be found elsewhere [19,20]. As preliminary characterization to establish the baseline for the as-received amorphous Fe-based coatings, X-ray diffraction patterns were used in conjunction with the EDS spectra, to identify the phases present in the unirradiated and thermally untreated specimens.…”

Operando identification of the point of [Mn2]O4 spinel formation during γ-MnO2 discharge within batteries

“…Collimation slits were used to set the sizes of the incident and diffracted beams, and the intersection of the two beam cross-sectional areas defined a gauge volume (GV) in space. [10,15,16] By positioning the GV inside the battery, diffraction data was collected at a well-defined spatial location as illustrated in For the 100 mA battery, a larger d i setting of 300 μm was used to better resolve the (110) reflection of ramsdellite. Batteries were "mapped" by positioning the GV at the top of the can and moving the battery, using an x-y-z stage, to scan the GV radially inward to the battery center.…”