Three-dimensional Mapping of Fatigue Crack Position via a Novel X-ray Phase Contrast Approach

X-ray absorption microtomography loses considerable sensitivity when it is applied to samples with high-aspect-ratio cross-sections, e.g. plates or compact tension samples. Synchrotron X-ray phase enhanced imaging is much more sensitive than absorption-based techniques to cracks with small openings, and phase imaging and stereometric techniques are developed in this paper for three-dimensional reconstruction of the interior of a sample in a way which avoids the limitations of conventional microtomography. The phase stereometric approach is applied to an Al compact tension sample containing a fatigue crack, and the crack positions are in good agreement with those determined with conventional microtomography.