The ultra-fine grained (UFG) aluminum with the grain size of 260 nm was fabricated by annealing for the severely plastic deformed A1100 alloy. This UFG aluminum showed the 0.2% proof stress (σ 0.2) of four times the stress that the conventional Hall-Petch relation showed. In this study, for the UFG aluminum, the fine-grained (FG) aluminum with the grain size of 960 nm and the coarse-grained (CG) aluminum with the grain size of 4.47 µm, dislocation density change during the tensile deformation was investigated by the In-situ XRD measurement using SPring-8. The dislocation density changed in four stages with increase in strain. The first stage was the elastic deformation region and the dislocation density hardly changed. Only in the CG aluminum, this stage was hardly observed and the stress in which the dislocation began to multiple (σ I) was almost 0 MPa. In the second stage, the dislocation density rapidly increased to ρ II in which plastic deformation became possible at constant strain rate. In the third stage, the change became moderately. In the fourth stage, the dislocation density rapidly decreased by the fracture of test pieces. Additionally, the σ 0.2-σ I were followed the conventional Hall-Petch relation regardless of grain size.

Orientation changes of a Cu single crystal with an initial orientation of {111} 〈112〉caused by cold rolling were analyzed using electron back scatter diffraction patterns obtained by scanning electron microscopy. The orientation changes were understood as the rotation around TD and the formation of band like structures parallel to RD was observed after the cold rolling.Multiple slip systems of the {111} 〈112〉single crystal operated by the cold rolling were discussed. Orientation changes after the cold rolling were explained reasonably by the operations of two different multiple slip systems. High angle grain boundaries were formed between the band like structures in the single crystals rolled to 30 and 50 reduction. Striped patterns observed on the TD plane in the region where one of the multiple slip systems operated were also discussed. The striped patterns were explained by small angle tilt boundaries consisting of arrays of edge dislocations on the slip planes.

Electrical resistivity and Vickers hardness of Alloy 625 due to cold rolling were measured, and, discussed with the microstructural change obtained using electron backscattered diffraction and X-ray diffraction. Both increase in dislocation density and grain subdivision due to rolling was observed. Although the electrical resistivity of the normal pure metals increases with increasing the rolling reduction, that of Alloy 625 initially decreased with increasing the rolling reduction of 70％. Then, the electrical resistivity slightly increased with increasing the rolling reduction of 80％. Up to the rolling reduction of 70％, the reduction of electrical resistivity is associated with K effect, which is the destroy of the short-range ordered domain due to the plastic deformation. On the other hand, Vickers hardness increased with increasing the rolling reduction. It was associated with the contribution of grain refinement, dislocation, solid solution, and sort-range order strengthening.