A comparative EBSD and micro-XRD study of the intergranular grain structure in CP-Ti

Abstract

Electron Backscatter Diffraction (EBSD) and scanning polychromatic X-ray micro-diffraction (micro-XRD) have been applied to study the intergranular grain structure in CP-Ti strip. Prior to synchrotron experimentation, a polycrystalline CP-Ti sample was electrochemically polished and a series of fiducial markers were placed on the surface to define a 500 μm×500 μm region of interest. Within this area EBSD was used to obtain an orientation map of the grains at the sample surface. Synchrotron polychromatic X-ray micro-diffraction data, collected on beamline 12.3.2 at the Advanced Light Source, was then used to map an area of 200×60 μm 2 within the region of interest. Comparison of the respective grain maps indicated an average grain size of ∼50 μm. Micro-XRD data was initially used to locate the same surface grains determined by EBSD. Based on comparison of the Euler angles, grain orientation maps from the two data sets were found to be in close agreement. The typical rolling texture found in CP-Ti was identified with the basal pole maxima tilted slightly toward the transverse direction. Subsequent 3D analysis of the Laue pattern intensity distribution of the surface grains revealed that some of the large grains identified by EBSD formed sub-cell structures below the sample surface.