In order to detect remainders in the internal cooling channels by non-destructive means with high accuracy

industrial computed tomography was used to scan the tested blade.The position displacement parameters between the tested blade and the standard specimen were calculated base on the rigid transformation and sinogram projection.Then the sinograms of the scanned slice and the corresponding standard slice were matched together in order to extract the sinogram of the remainders and the reconstructed images of them were obtained.The experimental results prove that this method can extract remainders in the internal cooling channels effectively.Compared to the traditional remainder extraction algorithm based on CT(computed tomography) image

the proposed algorithm is realized in the projection domain

and it is rarely affected by projection data incompleteness

scanning system bias and the reconstruction artifacts

so it has a higher accuracy.