Computed tomography (CT) is a fast and non-destructive method for material and component examination. It enables a three-dimensional representation of the internal and external structure of objects with a detail detectability which goes down into the micrometer range. CT analysis is of great value for the efficient new development and further development of materials and production processes. By means of material samples, it is possible to determine within a short time whether, for example, a good infiltration of the reinforcing fibers with the plastic matrix has taken place during the manufacture of organic sheets, and whether the material contains pores or other flaws. As a consequence, the processing temperatures and pressures, for example, can be adapted, or differing matrix polymers can be compared regarding their workability. The success of the procedure adaptation can, in turn, be verified by means of CT images.
As CT can be applied largely independent of the material, an almost unlimited range of applications exists beyond these examples. With CT, not only classical materials such as plastics, wood-based materials, building materials or metals can be investigated but also, in particular, hybrid materials, which are increasingly gaining in significance. For hybrid components made from fiber composite plastics and metal, the interface quality between plastic and metal can, for example, also be assessed, in addition to the fiber-matrix bonding in the composite material. Furthermore, CT is also suitable for geological, biological and archaeological samples.
Our computer tomograph can be very flexibly utilized, due to its being furnished with a large measuring chamber, two x-ray tubes and two detectors. On the one hand, large objects with a diameter of up to 500 mm can be detected and on the other hand, resolutions down into the lower micrometer range are possible.
CT uses the X-ray characteristic of penetrating objects and thereby being weakened in dependence on the material and the path length. From a series of 2D X-ray images of the examined object from different camera angles, generally by gradual rotation of the test object, the 3D volumetric representation of the object is reconstructed with the assistance of a computer. The 3D volume is comprised of a large quantity of so-called voxels - the 3-dimensional analogs of pixels - with absorption-specific gray values. The edge length of the voxel thereby determines the detail detectability of the CT scan. The measurement duration is taskdependent and lasts between a half-hour and two hours.