The multiscale plastic deformation in the vicinity of the crack tip was studied with neutron and x-ray microbeam diffraction. The results help to understand the overload effect, which induced large plastic deformation causing hierarchical dislocation arrangement around the crack tip. From neutron diffraction measurement anisotropic line broadening was observed in front of the crack tip. Furthermore, Laue patterns obtained from microbeam diffraction at different locations near the crack, provide a better spatial resolution and show alternating regions with high and low dislocation density. Orientation dependence on (hkl) of both strains and line broadening was observed indicating non random dislocation arrangement. Dislocation density and arrangement was evaluated from the line width and profile behavior for several crystallographic families. Lattice strains were analyzed by GSAS. Comparison of the results obtained with GSAS and line profile analysis allowed to understand the change of hierarchical dislocation density distribution and strain in different plastic zones. Overall, the dislocation density was found to decrease with the distance from the crack tip.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/8208 must be provided.

1. 3D Characterization of Defect Gradients in the Near Surface Microstructures and BulkAlloys Via Polychromatic Microdiffraction
2. X-ray MicroBeam Characterization of the Near Surface Nanostructure Layer in Ti After Friction Stir Processing
3. Characterization of Growth Defects in GaN Layers withX-ray Microbeam
4. Residual Stresses, Thermomechanical Behavior and Interfaces in the Weld Joint of Ni-based Superalloys
5. Characterization of chrystallographic properties and defects via X-ray microdiffraction in GaN(0001) layers