Measurement of small misorientations using electron back scatter diffraction

摘要

This paper concerns the determination of small misorientations using electron back scatter diffrecation (EBSD).Generally EBSD is used to measure crystal orientations from which misroientations can be calculated.Repeated measurements on undeformed Si showed that the calculated misorientations have an error of +-0.25deg associated with the misorientation angle,while the misorientation axis generally has a larger error.The uncertainty in the calculated misorientation axis increases significantly as the misorientation angle decreases,so that for misorientation angles below approx 5 deg the misorientation axis is essentially undeterined.A new method in which the misorientation is measured directly from a pair of EBSD patterns is presented.The analysis uses a cross-correlation procedure to determine the relative positions of two or more similar features in the pair of EBSD patterns.Measurements from a Si specimen deformed in single slip indicate that the new method gives reliable misorientations (axis and angle) for misorientations of approx 0.25 deg or greater.