Observation and analysis of materials with synchrotron radiation

After the explanation of the fundamental theory of x-ray tomography, a few examples for the application are reviewed. Tomography provides three-dimensional images of heterogeneous materials, and offers an unprecedented insight into their internal structure. The in situ high-resolution synchrotron radiation x-ray computed microtomography has been applied to visualize and qualify the ductile fracture process of a notched Al alloy, nanoscopic precipitates in a Al alloy, and the fatigue crack propagation process in an Al-Mg-S alloy. The application of fast microtomography has made it possible to observe real crack initiation and propagation behaviors. In situ observation has been performed with x-ray diffraction technique using synchrotron radiation to observe growth behavior of the Fe-Zn intermetallic compounds, and directional solidification process during welding. Hard x-ray photoelectron spectroscopy using high-brilliance synchrotron radiation has been applied to investigate Cu segregation in oxide-metal interface during metal-dusting corrosion. Small-angle x-ray scattering is useful for microstructure analysis of age-hardenable alloys containing precipitates with several to several tens of nanometer in size. On the other hand, ultra small-angle x-ray scattering is appropriate to examine much larger precipitates where size is typically around one micrometer. The structure and formation kinetics of Guinier-Preston (GP) zone in an Al-1.7at%Cu alloy during aging at 248 K, and dynamical structural change during reversion process of A-6.8 and 15 at% Zn alloys above GP zone were investigated by the small-angle scattering technique of synchrotron radiation. Microstructure evolution of nano-quasicrystals precipitated in ZrCuPt metallic glass ribbons during annealing has been examined by in situ small-angle scattering and wide angle diffraction. (author)