Recent trends in X-ray-based characterization of nodular cast iron

Through various examples, this short review presents the main X-ray-based techniques that are available to characterize nodular cast iron at the microstructural level. Emphasis is placed on the enormous potential offered by the recent developments in X-ray tomography, X-ray diffraction, and digital volume correlation, which allow collecting microstructural and micromechanical information in 4D (3D plus time) during both casting and subsequent mechanical loading. The goal is to demonstrate that for nodular cast iron, which has an inherently three-dimensional, composite microstructure, X-ray-based techniques provide some significant advantages over conventional microscopy. For this reason, these techniques can be instrumental in unveiling the mechanisms controlling both the formation of the microstructure as well as its micromechanical behavior during in-service loading, thus paving the way to the development of improved process–structure–property relations.