Insight casting with non-destructive evaluation

Cast materials are used wherever the highest demands are placed on the mechanical properties of the component while at the same time the component design is complex. However, since the production of cast work pieces is relatively expensive, the greatest possible exploitation of the material potential is aimed at. Since, in addition, the occurrence of imperfections such as discontinuities and microstructure degenerations inside the casting cannot be ruled out due to the manufacturing process, tools are required which, in addition to the localization of imperfections, also provide 'Information which allow quick and documented decisions to be made as to whether and where defects found in the component are permissible. In addition to regulär quality assurance, non-destructive testing is therefore receiving increasing attention when it comes to the non-destructive determination of material properties along the entire product life cycle. The insitu determination of the degree of purity of a melt, the homogeneity of a performed heat treatment, the exact Position and Orientation of an imperfection, the detection of a crack and the online tracking of crack propagation as well as a quantitative characterization of microstructure degenerations are only some of the developments currently being investigated by Fraunhofer IZFP. The aim is always to draw conclusions about quality and process relevant material properties from non-destructively determined Parameters. With respect to this goal two approaches, a physical one and a Statistical one are pursued at Fraunhofer IZFP. Both approaches are presented in this paper and their potential with respect to the characterization of cast materials is demonstrated using two examples. The presented applications address the purity characterization of aluminum melt and the quantitative characterization of microstructure degenerations in spheroidal graphite cast iron.