Authors: T. Ishizaki, K. Teshima, N. Saito
Affilation: National Institute of Advanced Industrial Science and Technology (AIST), Japan
Pages: 421 - 424
Keywords: layered double hydroxide, corrosion, inhibitor, magnesium alloy
Magnesium is one of the lightest engineering materials. Thus, it is expected that magnesium and its alloys are applied to aerospace, aircraft, automobile, and railway. However, they have a defect which is extremely low corrosion resistance. It is considerably difficult to completely suppress the corrosion reaction on the magnesium and its alloy surfaces. Thus, it is necessary to develop anticorrosion film with the self-repairing functionalities for magnesium and magnesium alloys. In this study, we tried to directly fabricate inhibitor molecule intercalated layered double hydroxide film on magnesium alloy. XRD profile revealed that the treated surfaces were well crystallized with a preferential hexagonal orientation along the  plane, which is a characteristic feature of the spontaneous texture axis of the inhibitor intercalated LDH film. The peak position corresponds to a d-spacing of 0.80 nm, which is lower than the d-spacing of the NO3- anion intercalated LDH film (0.90nm), indicating that the inhibiting molecules are intercalated. The corrosion protection capability was investigated using electrochemical measurements. Potentiodynamic polarization measurement revealed that the corrosion resistance of the inhibitor intercalated LDH film covered magnesium alloy was greatly improved compared with the untreated magnesium alloy and LDH film without inhibitor covered magnesium alloy.