Ultrasonic computed tomography considerations in the NDE of solid materials

A research effort was carried out to assess the feasibility of utilizing ultrasonic computed tomography (UCT) to determine quantitatively the porosity content and distribution within various test specimens. Index of refraction (or velocity) tomography, as opposed to attenuation tomography, was used because of the many complications encountered when using the latter and its inherent inconsistency in determining porosity content. It is demonstrated that, with suitable measures taken to account for beam refraction and other related effects, ultrasonic tomography could indeed be used for porosity location and quantification