2.3 Ion milling Ion milling including focused ion beam (FIB) and ordinary ion milling products (Flat Ion Milling System, Hitachi IM-3000), is a process using ion beam (Ga+ or Ar+) to remove the surface of target material. It has been widely used in preparing TEM samples and now is a very universal polishing method for EBSD preparation of almost all materials. EBSD combined with a dual-beam FIB has been used in investigating 3D-EBSD image [16]. With the help of FIB ion milling, TEM and EBSD