The imaging of failure in structural materials by synchrotron radiation X-ray microtomography

Elucidating the origin of electroplasticity in metallic materials

Dynamic fracture of C/SiC composites under high strain-rate loading: microstructures and mechanisms

Anisotropic deformation of extruded magnesium alloy AZ31 under uniaxial compression: A study with simultaneous in situ synchrotron x-ray imaging and diffraction

Intragranular void formation in shock-spalled tantalum: Mechanisms and governing factors

We present a dynamic strain field mapping method based on synchrotron X-ray digital image correlation (XDIC). Synchrotron X-ray sources are advantageous for imaging with exceptional spatial and temporal resolutions, and X-ray speckles can be produced either from surface roughness or internal inhomogeneities. Combining speckled X-ray imaging with DIC allows one to map strain fields with high resolutions. Based on experiments on void growth in Al and deformation of a granular material during Kolsky bar/gas gun loading at the Advanced Photon Source beamline 32ID, we demonstrate the feasibility of dynamic XDIC. XDIC is particularly useful for dynamic, in-volume, measurements on opaque materials under high strain-rate, large, deformation.

Note: Dynamic strain field mapping with synchrotron X-ray digital image correlation.

Plate-impact experiments were conducted to study the features and mechanisms of void nucleation and growth in the polycrystalline of pure aluminum under dynamic loading. Soft-recovered samples have been analyzed by metallographic microscopy, electron back scattering diffraction (EBSD), and synchrotron radiation x-ray tomography technology. It was found that most of the void nucleation in grains neared the boundaries of “weak-orientation” grains and grew toward the grain boundaries with fractured small grains around the boundaries. This was mainly caused by the accumulation and interaction of slip systems in the “weak-orientation” grains. In addition, the micro voids were nearly octahedron because the octahedral slip systems were formed by 8 slip planes in the polycrystalline of pure aluminum. The EBSD results are consistent with the three-dimensional structure observed by synchrotron radiation x-ray.

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X. X. Ran

Papers

Note: Dynamic strain field mapping with synchrotron X-ray digital image correlation.

Nucleation and growth of damage in polycrystalline aluminum under dynamic tensile loading