Texture analysis by electron diffraction

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Electron diffraction methods for the determination of individual grain orientations and selected area diffraction (SAD) pole figures are briefly reviewed. The standard techniques of orientation determination grain‐by‐grain are the interpretation of selected‐area electron spot and microbeam Kikuchi diffraction patterns with a transmission electron microscope (TEM). Electron‐transparent thin samples are required. Specimen areas smaller than 500 nm or 10 nm in diameter, respectively, can be studied. Alternatively, selected area pole figures can be measured on a TEM. This technique is similar to the conventional transmission x‐ray method. The orientations of grains in a bulk sample are obtained with a scanning electron microscope (SEM) from back‐reflection Kikuchi patterns (i.e. electron backscattering patterns) or from channelling patterns. Spatial resolution is approximately 1 μn or 5 μm, respectively.Individual grain orientation and pole figure measurements can be performed on‐line by interfacing the electron microscope with a computer. Outstanding advantages of texture measurement by electron microscopy over x‐ray and neutron diffraction are the ability to image the microstructure of the sampled area which complements texture measurement, and the high spatial resolution in diffraction and imaging modes. Experimental results of individual grain orientation measurement may be represented by inverse pole figures, orientation distribution functions, and misorientation distribution functions.