Abstract:
X-ray computed tomography (XCT) scans can be used to determine the presence of metals and to identify these metals provided that sample size is fairly large and that suitable scanning conditions are implemented. Mean and standard deviations of HU values are determined for five metal alloys used in numerous modern industrial applications: one magnesium-based (light metal, atomic number 12) AZ31b, two aluminum-based (light metal, atomic number 13) AA1050 and AA2011, one iron-based (heavier metal, atomic number 26) AISI1006 steel, and one copper-based (heavy metal, atomic number 29) CDA272 brass. For each metal alloy, the study utilizes 16-bit XCT scans of three sheet thicknesses (1.5, 3, and 6 mm) and at five voxel sizes (0.0113, 0.0177, 0.0254, 0.0310, and 0.0454 mm3). Also studied are three levels of X-ray tube current (50, 100, and 200 mA) and two levels of voltage (120, 140 kVp). Results show that the standard deviations of the Hounsfield unit peaks decrease with increasing sample thickness and increasing tube voltage and current. By virtue of varying the scanning parameters, the spread of the mean Hounsfield units is decreased by 50%, 60%, 71%, 47%, and 47% for AZ31b, AA1050, AA2011, AISI1006, and CDA272, respectively. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
