Determining dislocation cell sizes for high-strain deformation microstructures using the EBSP technique.

The effect of several data collection and processing choices has been examined for high-resolution electron back-scatter pattern (EBSP) investigation of a highly deformed sample. The results were compared with a transmission electron microscope (TEM) investigation of the same sample. The estimated dislocation cell size was examined as a function of data cleaning strategy, line intercept vs. reconstruction method, critical misorientation angle definition and step-size. The best agreement with the TEM results was obtained using a modified relative reconstruction algorithm on fine step-size maps allowing some of the noise in the data to be overcome. Step sizes of up to one-quarter the average cell size yielded similar values for the estimated average cell size. As a result of the mixture of both high- and low-angle boundaries, single diffraction condition TEM images may give larger cell size estimates than the EBSP data. Orientation noise in the EBSP data, however, still limits the extent to which quantitative information can be extracted.