X-RAY TEXTURE ANALYSIS IN MATERIALS AND EARTH-SCIENCES

The texture of a polycrystalline material is quantitatively defined by the orientation distribution function of the crystallites. In additio n, higher-order textural quantities may also be considered such as the mis-orientation distribution function which describes the pair distri bution of neighbouring crystals, texture fields, and multi-phase textu res, thus approaching a comprehensive description of the statistical c rystallography of polycrystalline aggregates. Textures of materials ca n be measured mainly by X-ray diffraction but also using neutron and e lectron diffraction. The original textural data are pole density distr ibution functions from which the orientation distribution function can be calculated. Textures have an influence on the properties of materi als and they originate from all kinds of anisotrop solid-state process es. This establishes the interest in texture in materials science as w ell as in the earth sciences as illustrated by some examples.