High-speed synchrotron X-ray phase contrast imaging for analysis of low-Z composite microstructure

The study of high performance composites such as plastic-bonded explosives under extreme conditions often requires innovative experimental techniques. Here, static synchrotron X-ray phase-contrast imaging (PCI) of simulated explosive materials has been performed at high speed in an effort to determine feasibility of imaging material response to dynamic, high-strain rate events (10 ²-10 ⁷ s ^-1). The microstructure of pristine materials, idealized composites and simulated explosive composites has been characterized with synchrotron PCI at the Advanced Photon Source. High spatial resolution (2 μm) of the microstructure was achieved with 5 μs exposures, and features such as interfaces, cracks, voids, and bubbles were clearly observed. The likelihood of obtaining sufficient phase information at even faster exposures (e.g., 0.2-0.5 μs) is shown to be high.