Neutron Scattering

Apart from the global description of the texture in the total orientation space, texture
can also be described by a certain number of texture model components, although this
description includes only restricted areas of the orientation space . Each component to be
described, for instance, by a Gaussian distribution curve is given by (1) a prefened orientation
g° locally restricted in orientation space, (2) a halfwidth b° characterizing the spread around g°
(sec Fig . 18 .19) and (3) an intensity 1 ° indicating the volume share of all crystallites belonging
to that component . The ODF approximation by means of texture components is expressed by
f(g) = R + Y- 1 ° f(g) (7) .
The quantity R gives the volume fraction of the randomly oriented crystallites, i .e. which are
not restricted in the orientation space . The component method [10] can be applied to
composite experimental pole figures, also of multi-phase geological material of any
ciystallographic symmetry .
5.2 Inverse Pole Figures
The mathematical procedure ofpole figure inversion includes the calculation of coefficients H
of so-called inverse pole figures . While the pole figures discussed so far are defmed for one
particular crystallographic direction [hkl] and variable sample orientations (compare equation
(5), the inverse pole figures represent shares of main crystallographic directions, e .g . basis
axis, face and body diagonal of the cubic ciystal system, in a fixed sample orientation (Fig .
18 .20) . Usually, the inverse pole figure is represented as stereographic projection with respect
to the crystal coordinate system KK, while the standard` pole figure is defmed as
stereographic projection with respect to the sample coordinate system KP (compare Fig . 18 .5) .
Fig . 18.20 : Inverse polefigure of a
cold drawn Al wire (sec (21) by
representation of the preferred
orientations of the most relevant
crystallographic directions (cubic
axis [100], face-diagonal [1101 and
body-diagonal [1111) inside the
sample . Pole densities are shown by
equilevel contour Unes in m . r. d.
6.0 Examples of Texture Analyses
Texture appears in a great variety . A multitude of different types is kown according to
different mechanisms of texture formation during ciystallization (grain growth) and reciystal-
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