Figure 3 shows the EBSD orientation maps with successful electropolishing on light metals before and after SPD [1,2,10]. It is well known that the pattern quality of the EBSD deteriorates with increasing density of defects like dislocations and accumulated strain in materials processed by SPD. Therefore, the microstructures without SPD (Figs. 3(a) and (c)) can be easily characterized by EBSD and the image quality (IQ) is very high. Materials processed by SPD are very difficult to be investigated by EBSD and, therefore sometimes non-indexed points (black points) present in the heavily deformed area (Fig. 3(d)). In general, the electropolishing parameters that work for materials processed by SPD can be used for the same material without SPD. The materials with higher atomic number like nickel and steel can yield stronger Kikuchi patterns, thus the sample preparation is not so critical.