Texture measurement with short-wave X-ray synchrotron radiation in the range of ! 9 0.1 A Ê is described. The measurements were carried out with the multipurpose diffraction instrument at the high-®eld wiggler, high-energy beamline BW5 at HASYLAB. The instrument was equipped with an on-line image-plate area detector for diffraction-image registration and a Eulerian cradle for sample orientation. The particular features of texture measurement with the BW5 instrument are: good resolution in the Bragg angle, extremely high angular resolution in crystal orientation (pole-®gure angles) and particularly high penetration depth of several millimetres to centimetres, comparable with that of neutrons but at high spatial resolution. Several examples illustrate the particular advantages of this method for texture studies using large or encased samples (in situ studies in complicated environments, such as cryostats, furnaces, vacuum or pressure chambers, with no serious window problems). This allows, among others, non-destructive texture analysis in technological parts and whole components. Because of the extremely high beam intensity (short exposure times) compared with all other methods of texture measurement, the new technique is particularly suited for the study of large sample series (as is often necessary in industrial applications).

The orientation distribution of the Widmannsta È tten plates was measured in a sample of the Gibeon iron±nickel meteorite. The measurements were made with high-energy synchrotron radiation at beamline BW5 at HASYLAB/DESY in Hamburg using a high-resolution`moving-detector' technique. The measurements reveal a continuous range of orientations stretching out from both sides of the Nishiyama±Wassermann orientation to the Kurdjumov±Sachs orientations, as well as a minor`spread-pipe' between the Kurdjumov±Sachs ends of neighbouring non-coplanar orientation variants.

The texture of a material can be calculated from several pole ®gures, which, in turn, are usually measured by one of several`step-scan' techniques. In these techniques, the ®nite step width limits the attainable orientation resolving power. In the present paper, the discontinuous step-scan technique is replaced by a continuous`sweeping' technique based on the continuous movement of an area detector during exposure. In this way, continuous two-dimensional`images' of pole ®gures are obtained, without the necessity of interpolation. Similar sweeping techniques are also being used to obtain continuous images of other sections and projections of the six-dimensional`orientation±location' space which characterizes a polycrystalline structure completely. The high potential orientation and/or location resolving power of these imaging techniques can only be reached with synchrotron radiation. In the present paper, the measurements were made at the high-energy (short-wavelength) beamline BW5 at HASYLAB/DESY in Hamburg. The high orientation and location resolving power implies the necessity to distinguish`grain-resolved' textures and microstructures (mainly in recrystallized materials) from`continuous' ones (mainly in deformed materials). Under certain conditions, it is thus possible to obtain the complete six-dimensional`orientation stereology' of grain-resolved microstructures. The new methods are illustrated with several examples, including technological applications.

In order to describe texture and microstructure of a polycrystalline material completely, crystal orientation g ¼ {' 1 È ' 2 } must be known in all points x ¼ {x 1 x 2 x 3 } of the material. This can be achieved by locationresolved diffraction of high-energy, i.e. short-wave, X-rays from synchrotron sources. Highest resolution in the orientation-as well as the location-coordinates can be achieved by three variants of a detector ''sweeping'' technique in which an area detector is continuously moved during exposure. This technique results in two-dimensionally continuous images which are sections and projections of the six-dimensional ''orientation-location'' space. Further evaluation of these images depends on whether individual grains are resolved in them or not. Because of the high penetration depth of high-energy synchrotron radiation in matter, this technique is also, and particularly, suitable for the investigation of the interior of big samples.

The coatings are composed of methyltrimethoxysilane (MTMS), tetraethylorthosilicate (TEOS) and silica particles (LUDOX TM50, size 35 nm) in differing concentrations. Further details on the preparation are given elsewhere [2,4,6] .