Intercalation of Y in Mg-Al layered double hydroxide films on anodized AZ31 and Mg-Y alloys to influence corrosion protective performance

Yttrium-doped Mg-Al layered double hydroxide films (MgAlY-LDHs) were firstly fabricated by a hydrothermal method on anodized AZ31 and Mg-Y alloys. The structure, morphology, and composition of MgAlY-LDHs were characterized by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectrometry (XRF), backscattered electron spectrometer (BSE), field-emission scanning electronic microscope (FE-SEM), energy dispersive spectrometry (EDS) and glow discharge optical emission spectroscopy (GDOES), respectively. The electrochemical behavior was investigated using polarization curves, electrochemical impedance spectroscopy (EIS), and immersion tests. The results indicated that the Y ions can be successfully intercalated in the MgAl-LDH lamella by isomorphous replacement, which can enhance corrosion protective performance and possess the self-healing ability of coatings. Furthermore, the in-situ growth of ternary LDHs film on high-strength Mg-rare earth (RE) alloys demonstrated the considerable potential of anti-corrosion protection for industrial application. The schematic representation of the growth mechanism and electrochemical behavior of MgAlY-LDHs nanosheet was put forward finally.