Texture (crystalline) - Characterization and Representation

Characterization and Representation

Texture can be determined by various methods. Some of them allow a quantitative analysis of the texture; others are only qualitative. Among the quantitative techniques, the most widely used is X-ray diffraction using texture goniometers, followed by EBSD-method (electron backscatter diffraction) in Scanning Electron Microscopes. Qualitative analysis can be done by Laue photography, simple X-ray diffraction or with the polarized microscope. Neutron and synchrotron high-energy X-ray diffraction allow access to textures of bulk material and in-situ analysis, whereas laboratory x-ray diffraction instruments are more appropriate for thin film textures.

Texture is often represented using a pole figure, in which a specified crystallographic axis (or pole) from each of a representative number of crystallites is plotted in a stereographic projection, along with directions relevant to the material's processing history. These directions define the so-called sample reference frame and are, because the investigation of textures started from the cold working of metals, usually referred to as the rolling direction RD, the transverse direction TD and the normal direction ND. For drawn metal wires the cylindrical fiber axis turned out as the sample direction around which preferred orientation is typically observed (see below).

• Four circles diffractometer, or Eulerian cradle, for texture measurement with X-ray diffraction

• χ mode for reflection measurement

• Ω mode for transmission measurement