Three-dimensional visualization of ductile fracture in an Al-Si alloy by high-resolution synchrotron X-ray microtomography

A direct three-dimensional visualization of the ductile fracture process under monotonic loading, in an Al-Si-Mg alloy specimen containing a fatigue pre-crack, has been conducted by means of the high-resolution X-ray computed tomography. Different morphology features of the crack viewed on different cross sections within the bulk of the specimen are detected. The isolated voids are distinguished from the microcracks. The evolution of the crack and voids as a function of the applied load are monitored and analyzed three-dimensionally. The advantages of the technique over traditional cross sectional observations are demonstrated, which facilitates to understand the fracture mechanisms in ductile materials, and to elucidate the fracture/microstructure interaction in non-uniform mediums