Observation and Modeling of (V)HCF Crack Initiation in Cast Nickel-base Superalloys for Aerospace Application

Crack initiation is a pressing problem in engineering application, which is currently accounted for in design with large safety factors due to the very large scatter it introduces in the lifetime of parts, especially when loaded in the (V)HCF regime. With our work we want to extend the understanding and modeling capabilities regarding this phenomenon. Using diffraction contrast tomography (DCT) the 3D grain structure of 5 specimens should be observed, while the casting porosity will be found via phase diffraction tomography. Afterwards, the specimens will be incrementally cycled and crack initiation will be detected using phase diffraction tomography. The collected data will be used to create a 1:1 virtual representation of each specimen on the grain scale. Crystal plasticity modeling and fatigue indicator parameters shell then be used to model the crack initiation process and compare the results with the experiment.