Quantifying microscale drivers for fatigue failure via coupled synchrotron X-ray characterization and simulations

Sven Gustafson (1) , Wolfgang Ludwig , Paul Shade , Diwakar Naragani (1) , Darren Pagan (2) , Phil Cook (3) , Can Yildirim (3) , Carsten Detlefs (3) , Michael D Sangid (1)

1 School of Aeronautics and Astronautics [Purdue]
2 CHESS - Cornell High Energy Synchrotron Source
3 ESRF - European Synchrotron Radiation Facility

During cyclic loading, localization of intragranular deformation due to crystallographic slip acts as a precursor for crack initiation, often at coherent twin boundaries. A suite of highresolution synchrotron X-ray characterizations, coupled with a crystal plasticity simulation, was conducted on a polycrystalline nickel-based superalloy microstructure near a parent-twin boundary in order to understand the deformation localization behavior of this critical, 3D microstructural configuration. Dark-field X-ray microscopy was spatially linked to high energy X-ray diffraction microscopy and X-ray diffraction contrast tomography in order to quantify, with cutting-edge resolution, an intragranular misorientation and high elastic strain gradients near a twin boundary. These observations quantify the extreme sub-grain scale stress gradients present in polycrystalline microstructures, which often lead to fatigue failure.

Domaines: Sciences de l'ingénieur [physics]; Matériaux

Sven Gustafson, Wolfgang Ludwig, Paul Shade, Diwakar Naragani, Darren Pagan, et al.. Quantifying microscale drivers for fatigue failure via coupled synchrotron X-ray characterization and simulations. Nature Communications, 2020, 11, ⟨10.1038/s41467-020-16894-2⟩. ⟨hal-03099952⟩