A Novel Approach to Fabricate Protective Layered Double Hydroxide Films on the Surface of Anodized Mg‐Al Alloy

In this work, anodic films consisted of a mixed oxide of aluminum and magnesium are developed on magnesium alloy by anodizing process. Then, MgAl‐layered double hydroxide (LDH) films are prepared by using this anodic film as a source of cations, without the introduction of any kinds of trivalent metal salts. After that, inhibitor anions of vanadate are intercalated into the interlayer galleries of LDHs through anion‐exchange process. LDH conversion films are investigated by scanning electron microscope, energy dispersive spectrum, X‐ray diffractometer, and Fourier transform infrared, respectively. Furthermore, the corrosion resistance of LDH conversion films are studied by potentiodynamic polarization, electrochemical impedance spectroscopy, and immersion test in NaCl solution, respectively. The results show that uniform and fine LDH films are successfully fabricated by using only anodic films, and the pores in anodic films are successfully sealed by LDHs. Moreover, the vanadate loaded LDHs exhibit better corrosion resistance compared to LDHs without vanadate.