X-ray computed tomography to investigate industrial cast Al-alloys

This paper describes the use of X-ray computed tomography (XCT) to inspect the internal defects of industrial Aluminum alloys die-casting, to justify the adequateness of super sealant resins in filling tiny holes, and to reduce the casting porosity of metals by the impregnation process. High-resolution 2D slice images were generated by a microfocus X-ray CT system with direct conversion Cadmium Telluride (CdTe) flat panel detector (FPD). Moreover, we were able to visualize the internal defects of the two different shapes of casting objects. The gray-value contrasts of the CT images were excellent to distinguish the resin material in the alloy samples after impregnation treatment. Furthermore, to determine the dimensions of internal defects, virtual sectioning was carried out to view the cross-section of the metal samples and dimensions of internal defects. Dual-energy X-ray computed tomography (DXCT) was used with an energy differentiation type 64-pixel linear array photon-counting line sensor for the material characterization. The impregnated resin part inside the castings defects was verified based on the effective atomic number with a 2.92% low error margin. Hence, this will be a useful qualitative and quantitative advancement to rapid and detailed non-destructive analysis within the die-casting industries in improving the quality of the impregnation process.