Supercube grains leading to a strong cube texture and a broad grain size distribution after recrystallization

This work revisits the classical subject of recrystallization of cold-rolled copper. Two characterization techniques are combined: three-dimensional X-ray diffraction using synchrotron X-rays, which is used to measure the growth kinetics of individual grains in situ, and electron backscatter diffraction, which is used for statistical analysis of the microstructural evolution. As the most striking result, the strong cube texture after recrystallization is found to be related to a few super large cube grains, which were named supercube grains. These few supercube grains become large due to higher growth rates. However, most other cube grains do not grow preferentially. Because of the few supercube grains, the grain size distribution after recrystallization is broad. Reasons for the higher growth rates of supercube grains are discussed, and are related to the local deformed microstructure

Measurements of the Curvature of Protrusions/Retrusions on Migrating Recrystallization Boundaries

Two methods to quantify protrusions/retrusions and to estimate local boundary curvature from sample plane sections are proposed. The methods are used to evaluate the driving force due to curvature of the protrusions/retrusions for partially recrystallized pure nickel cold rolled to 96% reduction in thickness. The results reveal that the values calculated by both these methods are reasonable when compared with the stored energy measured by differential scanning calorimetry. The relationship between protrusions and the average stored energy density in the deformed matrix is also investigated for partially recrystallized pure aluminum cold rolled to 50%. The results show that the local deformed microstructure as well as local heterogeneities have to be analyzed in order to understand the formation of the protrusions