During the complex manufacturing process of castings, various defects can occur that are not only on the surface. Inside, they can sometimes have a major impact on the stability of the part. However, incorrect geometries also make casted parts useless for later assembly. This is why it is important to detect defects reliably and early on. This is possible thanks to X-ray technology – with only one scan!
Pores describe spherical gas inclusions which are caused by the gasification of e.g. release agents or due to inadequate die venting.
Contaminations and an excessively high gate velocity can, for example, be reasons for the development of crack structures or thermal fatigue.
Shrinkage holes are sharp-edged, gas-empty cavities that are often connected to each other. They are formed when the material solidifies. The reasons for this are, for example, too low holding pressure or suboptimal position of the gate.
Inclusions are material components that are usually harder than the base material. They are caused, for example, by contaminated casting material.
This defect describes lines or grooves which are caused by a too low molding or melting temperature, sometimes also by a too long mold filling time.
This defect describes areas of the casting that are not or not completely filled in, or whose contours are not clearly reproduced, for example due to insufficient plunger speed or insufficient holding pressure.
Spongy areas are accumulations of small pores or shrinkage holes which can severely impair the stability of the casting.
The breakage or disintegration of a sand core can be caused, for example, by a non-optimal mould material composition or excessive thermal stress on the casting material. This changes the structure of the mold, so that the cast component has incorrect geometries.
Flashes are thin metal foils on the casting, caused for example by a too high gate velocity or an incorrectly adjusted clamping unit.
The reason for bulging in the form of blisters on the casting surface is, for example, too high a casting temperature or plunger speed in the second phase.
Often molding sand or salt remains inside the casting after decoring. With X-ray, this becomes visible and the part can be cleaned and then further processed.
Particularly in the case of long, heavy castings, deformation may occur during further transport, if the material has not yet completely cooled down. These deformations become visible in a target/actual comparison, for example.
If mistakes are made when positioning the core in the mould before casting, the geometries of the casting no longer match the CAD model. The component is, thus, no longer usable for assembly.