Mutiscale Plastic Deformation near a Fatigue Crack from Diffraction
After an overload was imposed during a constant amplitude fatigue experiment, a retardation period was observed. The deformation in the vicinity of a crack tip was studied using neutron and x-ray microbeam-diffraction techniques, which provide millimeter and submicrometer spatial resolutions, respectively. From the neutron-diffraction measurements, compressive lattice strains and higher dislocation densities at the macroscale were observed in front of the crack tip, which indicates a plasticity induced crack-closure phenomenon. Furthermore, Laue patterns obtained from the microbeam diffraction at different locations near the crack tip show alternating regions with high and low dislocation densities at the mesoscale.
R. Kozubski, G.E. Murch and P. Zięba
Y. Sun et al., "Mutiscale Plastic Deformation near a Fatigue Crack from Diffraction ", Solid State Phenomena, Vol. 129, pp. 151-156, 2007