Benefits of tomography in foundry industry

Industrial tomography, derived from medical technologies (scanner, MRI), is beginning to spread to the foundry industry. This non-destructive testing technology enables 3D visualization, from both inside and out, of highly complex geometries. A distinction needs to be made between micro-tomographs, which offer micrometer resolution and are used in R&D on samples or specimens, and production tomographs, which can scan entire parts (200 x 200 x 500 mm) but with a lower level of resolution (100 µm to 200 µm).

In production, tomography can be used not only to locate and quantify internal defects, but also to carry out geometric checks on prototype parts. In particular, geometrically complex internal core areas can be inspected without cutting.

Tomography is mainly used for automotive applications on aluminum parts (cylinder head, engine block, piston). However, there are industrial applications in other fields (aeronautics) or for other alloys (nickel-based).

At the R&D stage, micro-tomography enables fine analysis of the microstructures of exotic materials (metal matrix composites, metal foam, semi-solid alloys) or reconstruction of the geometry of internal defects for structural calculation purposes, to quantify the impact of casting imperfections on mechanical strength.

There are a large number of suppliers of industrial tomographs (Yxlon, General Electric...), as well as numerous subcontractors (Tomo Adour...).

Tomography in the foundry is in competition with other, much more widely used, means of conventional non-destructive testing (radiography and radioscopy). Although it is more expensive and does not allow rapid part inspection, tomography is the only tool that can be used to inspect non-accessible internal zones of parts, quantify defects and position them in space with precision.

The aim of this article is to review the state of the art in industrial tomography (elements of a tomograph, suppliers, service providers, available equipment) and to highlight the contributions of this technology in the foundry field, both in production departments and in R&D.