3-D Measurement of Deformation Microstructure in Al(0.2%)Mg Using Submicron Resolution White x-ray Microbeams

Abstract

ABSTRACTWe have used submicron-resolution white x-ray microbeanis on the MHATT-CAT beamline 7-ID at the Advanced Photon Source to develop techniques for three-dimensional investigation of the deformation microstructure in a 20% plane strain compressed Al(0.2%)Mg tri-crystal. Kirkpatrick-Baez mirrors were used to focus white radiation from an undulator to a 0.7 × 0.7 μm2 beam that was scanned over bi- and tri-crystal regions near the triple-junction of the tricrystal. Depth resolution along the x-ray microbeam of less than 5 microns was achieved by triangulation to the diffraction source point using images taken at a series of CCD distances from the microbeam. Computer indexing of the deformation cell structure in the bi-crystal region provided orientations of individual subgrains to ∼0.01°, making possible detailed measurements of the rotation axes between individual cells.