Understanding damage evolution in silicon-molybdenum alloyed cast iron through 3D imaging on multiple length scales

Ductile cast irons (DCI) alloyed with silicon and molybdenum (high SiMo-alloys) are commonly used in engine components where materials that can withstand harsh conditions are needed, e.g., in manifolds of the exhaust systems. However, for a detailed understanding of the micromechanical behavior of the materials, an in-situ 3D approach is needed. Here we propose a methodology combining digital volume correlation based on x-ray tomography with line beam and scanning 3DXRD. This combination of techniques will allow us to study intragranular variation of strain and orientation, follow grains even after yield, and obtain information on the shapes and sizes of the grains in the material. This also makes it possible to extract local stress-strain curves from different regions of the sample. Such information will be very useful in understanding the micromechanics of the materials, in terms of e.g. yielding behavior, and can also be used to calibrate numerical material models.