3D characterisation of the nucleation of a short fatigue crack at a pore in a cast Al alloy using high resolution synchrotron microtomography

In situ X-ray microtomography is used to visualize the nucleation and growth of a fatigue crack in the bulk of a cast Al alloy. At the end of the fatigue test, the three-dimensional grain structure is revealed by means of a Gallium infiltration technique. The simultaneous visualization of the crack with the surrounding grain structure allows one to correlate irregularities in the crack front shape with the local microstructure of the material.