Neutron and X-ray Microbeam Diffraction Studies around a Fatigue-Crack Tip after Overload
- ORNL
- University of Tennessee, Knoxville (UTK)
- Los Alamos National Laboratory (LANL)
An in-situ neutron diffraction technique was used to investigate the lattice-strain distributions and plastic deformation around a crack tip after overload. The lattice-strain profiles around a crack tip were measured as a function of the applied load during the tensile loading cycles after overload. Dislocation densities calculated from the diffraction peak broadening were presented as a function of the distance from the crack tip. Furthermore, the crystallographic orientation variations were examined near a crack tip using polychromatic X-ray microdiffraction combined with differential aperture microscopy. Crystallographic tilts are considerably observed beneath the surface around a crack tip, and these are consistent with the high dislocation densities near the crack tip measured by neutron peak broadening.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 941041
- Journal Information:
- Metallurgical and Materials Transactions A, Vol. 39A, Issue 13
- Country of Publication:
- United States
- Language:
- English
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