Normally, the samples cannot be used for EBSD after 1 μm diamond polishing. There are three main methods (electropolishing, silica polishing and ion milling) for the final polishing of EBSD samples to achieve good quality of patterns. 2.1 Electropolishing Electropolishing is a popular polishing method for the final step of EBSD preparation. It is one of the most effective methods for samples processed by SPD because it removes the microstrain induced by mechanical polishing. Electropolishing is a process by which surface material is removed from the sample by passage of electric current while the sample is made an anode (or positive terminal) in a designed solution. In general, the fresh surface which is easy to oxidize is recommended to be electropolished below room temperature. Sample preparation for some materials like Mg alloys, which is known to be very difficult, should be performed carefully. EBSD observation should be done immediately followed by electropolishing due to the easy oxidation on free surface. The electropolishing parameters of some commonly used materials are listed in Table 2. It can be seen that almost all materials require a subzero temperature to avoid the oxidizing problem. The electrolytes of AC2 and A3 are the product names of Struers Company. More information can be found from Ref. [8]. Normally, the electrolytes that are used to produce TEM thin foils can be used on electropolishing of bulk specimens [9]. For some materials like magnesium alloys, it is very useful to have an additional mechanical polishing with diluted OPS solution just before electropolishing [10]