Alumina, aluminium nitride and aluminium composite coating on 0.45% C steel by using a plasma source ion implantation and deposition (PSII&D) system

Al sub(2)O sub(3), AlN and Al composite coating was synthesized on 0.45% C steel sample to improve its corrosion resistance ability by using a plasma source ion implantation and deposition (PSII&D) system. The PSII&D is an extension of PSII by the combination of steady-state gas plasma and pulsed metal plasma. The gas plasma is produced by magnetic multipole filament discharge (or glow discharge) and the metal plasma is produced by pulsed cathodic arc discharge. The electrochemical corrosion test of the coating shows that the corrosion resistance ability of the coated 0.45% C steel sample was greatly improved. The microstructure, surface compositions, depth profile, bonding environment and morphology of the coating were investigated by X-ray diffraction (XRD), Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy. The results show that the coating is formed by Al sub(2)O sub(3), AlN and Al. The improvement in corrosion resistance ability of 0.45% C steel is due to the formation of the composite coating.