An overview of computed tomography in corrosion science

Abstract

Computed tomography (CT) is used in many fields from medicine to materials science. CT covers a range of different techniques with most types falling into X-ray or electron generated. Generally, X-ray CT is nondestructively, electron techniques are a mixture: for nontransmission electron techniques (e.g., backscatter electrons) the sample needs to be sectioned, whereas transmission (such as TEM) can be done nondestructively. X-ray CT has been used to address a range of problems in corrosion from determining pit volumes in metals to determining the transport paths of inhibitor molecules within paint systems. Electron techniques have also been used with serial sectioning being the most common. Atom Probe tomography is another CT technique which recreates 3D volumes of a sample at the nanoscale and is based on ion position detected after ablation or evaporation. This overview highlights some of the work that has been performed in these areas.