Optische Kohärenztomografie und 3D-Röntgen-Computertomografie Zwei Methoden zur Zerstörungsfreien Materialprüfung und Dimensionellen Messung: Zwei Methoden zru zerstörungsfreien Materialprüfung und dimensionellen Messung

Optical coherence tomography (OCT) is a novel non-invasive technique, which permits high-resolution cross-sectional imaging. The physical principle of this method is the interferometric interference of Infrared-light waves, which are scattered from different depths of the sample with a reference wave. The backscattered intensity gives information about the sample and can be used to calculate a cross-sectional picture of the sample. OCT can be used for materials characterisation as well as for dimensional measurements. Micro-X-ray-Computed tomography (μ-CT) is a radiographic NDT-method, which has become very popular in the last years. A CT-scanner with a micro-focus tube and a matrix-detector generates a series of X-ray attenuation pictures, which are used to produce computed reconstructed images of an object. CT can be used for all materials and because of its advantageous features it has become quite popular in science and industry. The main advantages are the reasonable high scanning speed and the high resolution. In this paper we compare OCT with μ-CT. We outline the advantages and disadvantages as well the reachable accuracies of both methods for the characterisation of different materials systems and for the measurement of dimensions. The materials, which were investigated, are fibre-reinforced composites, polymeric foams, complex polymeric parts, multilayered foils, a laminate structure and various test structures and parts.