Phase contrast radiology using non-monochromatic synchrotron X-ray successfully imaged the grain boundaries of Al and AlZn alloy without using a contrast agent. Combining the high penetration of X-ray and the possibility of 3D reconstruction by tomography or stereography method, this approach could be very used for the non-destructive characterization of polycrystalline materials. By examine the images with 3D perspective, it was possible to locate observed void-like defects which lay only at the grain boundary and originated in the last stage of the rolling process. The Ga liquid metal diffusion in the AlZn alloy was studied under various temperature and stress conditions. High-resolution images, ~2μm, of Ga liquid metal diffusion in AlZn were obtained in real time and diffusion paths along grain boundaries and surfaces were clearly identified. Embrittled AlZn responded to the tensile stress and fractured in a markedly different manner than did pure AlZn. These results, although expected from the known weakening effect of the liquid metal embrittlement demonstrated nevertheless that this particular radiological method was entirely capable of yielding dynamic data at the μm-scale.

Grain Boundary Imaging, Gallium Diffusion and the Fracture Behavior of Al–Zn Alloy – an in situ Study. W.L.Tsai, Y.Hwu, C.H.Chen, L.W.Chang, J.H.Je, H.M.Lin, G.Margaritondo: Nuclear Instruments and Methods in Physics Research B, 2003, 199, 457-63