Mapping type III intragranular residual stress distributions in deformed copper polycrystals

Cross-correlation-based analysis of electron backscatter diffraction patterns has been used to map the intragranular residual stress variations in polycrystalline copper samples deformed to different plastic strain levels of 0%, 2%, 6% and 10%. We map the deviation from the mean stress within each grain and present histograms of stress levels mapped over many grains which show a central Gaussian-like peak with non-Gaussian tails at the higher stress magnitudes. The width of the peaks increased with increasing plastic deformation and the tails became more obvious. Plots correlating maximum in-plane shear stress and distance to the nearest grain boundary demonstrate that stress hot spots tend to accumulate near grain boundaries. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.