Mesoscale structural characterization within bulk materials by high-energyx-ray microdiffraction

A novel diffraction technique for the local three-dimensional characterizat ion within polycrystalline bulk materials is presented. The technique uses high-energy synchrotron radiation (40 keV <E < 100 keV), which penetrates d eeply into materials. Focusing broadband optics have been developed that pr ovide the required intensity and spatial resolution perpendicular to the in cident beam. A focus size of 1.2 mum was achieved. Modified crossed-beam te chniques are being developed that define the longitudinal resolution, i.e., the component of the gauge volume parallel to the incident beam. We presen t experimental evidence that a longitudinal resolution down to 10 mum can b e obtained. Fundamental materials properties such as the strain/stress stat e, grain-orientation, -size, and -surface topology can be probed and mapped in three dimensions in favorable cases. Imbedded volumes and interfaces be come accessible. The technique is nondestructive and allows for in situ stu dies of samples in complicated environments. A dedicated experimental stati on has been constructed at the ID11 beamline of the European Synchrotron Ra diation Facility. On-line two-dimensional detectors and conical slits have been developed. Four examples of applications are presented.