Advances in Automatic EBSP Single Orientation Measurements

A completely automated system which couples automatic analysis of electron backscatter diffractionpatterns (EBSPs) with precise movement of the sample in the SEM is described. The Houghtransform is implemented into an existing technique for identifying lattice orientation throughautomatic analysis of EBSPs. The ability of the Hough transform approach to correctly identifydiffraction bands is quantitatively compared with the Burns algorithm. Both methods were tested on1000 EBSPs from well annealed oxygen-free, electrical grade (OFE) copper, 120 patterns from as-castcommercially pure aluminum and 106 patterns from 40% channel-die compressed aluminum. Onlyslight differences were found in the ability of the methods to correctly identify bands in the sampleEBSPs. The three test runs resulted in 95-99% (OFE Cu), 97.5-99% (as-cast AI) and 81-85%(deformed AI) correctly determined orientations (less than 5° off the manually determined referenceorientations). The limits in the ability of the band detection algorithms to fix the bands exactly arediscussed. To obtain the orientation which satisfies the detected bands most completely, a method ofaveraging solutions obtained from different triplets of bands is introduced.