Doublely-doped Mg-Al-Ce-V2O74- LDH composite film on magnesium alloy AZ31 for anticorrosion

A doublely-doped layered double hydroxide (LDH) film was produced on an anodized magnesium alloy AZ31. The Ce-doped Mg-Al LDH film was prepared by in-situ hydrothermal treatment method, and the intercalation of vanadate was realized by ion-exchange reaction. The structure, morphology and composition of as-prepared LDH film were investigated by X-ray diffractometer, field-emission scanning electronic microscope and energy dispersive spectrometry. Results indicated that a uniform and compact LDH film was formed and the intercalation of Ce3+ and vanadate would change the crystal structure of LDHs. The results of the potentiodynamic polarization, electrochemical impedance spectra, hydrogen evolution and corrosion weight loss tests showed the Ce3+ and vanadate anions significantly improve the impedance of LDH film, and the active double-doped LDH film could effectively protect the magnesium substrate from corrosion.