Improvement of industrial acceptability criteria depends both on the verification of the defects visible with conventional techniques and the determination of the relationship between the residual life and the defect geometry, which in turn require a high definition of the defect dimension and position.
While fracture mechanics is a well-established technique for relatively long cracks, very little is known at the moment relatively to the early development of small crack, that is the transition phase from the onset stage to the propagation stage of the crack growth. The assessment of fracture mechanics techniques for small crack problems depends strongly on a high definition of defect location and geometry.
In order to overcome these problems, we started to investigate whether a good definition of defects position and dimension was achievable using the novel phase sensitive imaging techniques available at SYRMEP beamline, Elettra, with encouraging results.
