Proposed combination of CAD data and discrete tomography for the detection of coking and lubricants in turbine blades or engines

Discrete tomography makes use of as much a priori information as possible in order to do tomographic reconstruction with as few projections as possible. The main requirement is that the investigated object consists only of two or of very few different materials (2–4) with a defined and constant attenuation coefficient. In addition, knowledge about geometrical properties can be used, like the existence of flat surfaces or cylindrical shapes. This paper proposes to use complete and definite information about the ideal reconstructed shape in order to detect deviations from that ideal shape in the actual sample. The idea is based on the works of A. Kuba et al. in [A. Kuba, L. Rodek, Z. Kiss, L. Ruskó, A. Nagy, M. Balaskó, Discrete tomography in neutron radiography, Nucl. Inst. & Meth. A 542 (2005) 376–382].