2. Measuring individual grain orientation and orientation microscopy

The measurement of individual grain orientations from Kikuchi patterns works in either transmission or backscatter mode, depending on whether thin sheets or solid materials are being studied. For orientation microscopy, it is essential that the crystal lattice orientations of all grains in the selected area are acquired without user intervention. Automated mapping is less tedious than interactive measurement and eliminates subjective grain selection. Orientation microscopy is performed by digitally scanning the primary beam spot on the sample, acquiring the stream of Kikuchi patterns with a fast digital video camera, and transferring the patterns to the computer, indexing the patterns and calculating the crystal lattice orientations of the grains under the beam spot.