A rotational and axial motion system load frame insert for in situ high energy x-ray studies

Abstract

High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert with a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability. C 2015 AIP Publishing LLC. [http://dx

Micromechanics and microstructure evolution during in situ uniaxial tensile loading of TRIP-assisted duplex stainless steels

“…1. A detailed description of the RAMS can be found in Shade et al [28]. During tensile tests at 45 o C the temperature was regulated by a furnace containing halogen bulbs and an elliptical mirror to focus the light onto the specimen.…”

Measured resolved shear stresses and Bishop-Hill stress states in individual grains of austenitic stainless steel

“…The energy of the beam was 56.618 keV. The load frame RAMS2 (Rotation and Axial Motion System, 2 nd build) [28] was used to load the sample in uniaxial tension while simultaneously allowing illumination of the sample over a rotation range of 360° in  with a sampling interval of 0.25°. In total five layers along the vertical 3-direction were scanned.…”

Combined near- and far-field high-energy diffraction microscopy dataset for Ti-7Al tensile specimen elastically loaded in situ

“…The experimental methods are generally described in Schuren et al [1], and the specific in situ loading equipment developed for this, as well as the subsequent experiments, is detailed in Shade et al [14]. Specifically, we utilized a rotational and axial motion system (RAMS) [14] to concurrently rotate the tensile specimen seen in Fig.…”

“…The material was then recrystallized at 955°C for 24 h and furnace cooled. This produced a single-phase material with a grain size of approximately 100 μm [1,14]. The tensile specimen was fabricated with the tensile axis transverse to the rolling and normal directions.…”

“…This offers a powerful tool to characterize the internal structure and mechanical behavior of deformable solids, which can be used to instantiate, and then later validate, micro-and meso-scale models such as crystal plasticity finite element modeling (CPFEM) [4][5][6]. The dataset presented in this paper represents concurrently collected near-field HEDM (nf-HEDM) [7][8][9] and far-field HEDM (ff-HEDM) measurements [10][11][12][13]; a first analysis of these data is contained in [14]. The nf-HEDM technique utilizes an area detector placed approximately 5 mm from the specimen and measures the grain morphology and local crystallographic orientations within and between grains, while the ff-HEDM technique measures the centroid and the average elastic strain tensor and crystallographic orientation in each individual grain.…”