Tribological behavior of graphene anchored Mg-Al layered double hydroxide film on Mg alloy pre-sprayed Al coating

Abstract A graphene (G)-Mg-Al Layered double hydroxide film (G-LDH) was designed and used to enhance the friction property of low-pressure cold gas sprayed (LPCGS) Al coating on Mg alloys. The G-LDH was fabricated hydrothermally by in-situ growth layered double hydroxides (LDH) on LPCGS G composite Aluminum (G-Al) coating. The pre-sprayed G-Al provides the source of Al for LDH and the G inserted in the G-Al coating is in-situ transferred and anchored into the LDH film. The characteristic of the samples was investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), Laser Roman Spectrometer (Raman), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray spectroscopy (XPS). The tribological performance was tested on ball on disc. Results demonstrate that a unique architecture of G anchored LDH film has grown on LPCGS G-Al coating. Moreover, the G-LDH exhibits the best friction property and load capability. A sound wear-resistance mechanism for the resulting coatings was proposed.