Research of the corrosion resistance of the C/Cr composite coating deposited by non-equilibrium magnetron sputtering

The corrosion resistance of the C/Cr composite coating on the GW93 rare magnesium alloy by non-equilibrium magnetron sputtering was studied through electrochemical methods as EIS and polarization curves which was validated by agravity. Microscopic structure were studied by SEM and AFM. The results show that the composite coating is constituted by chromium layer, transition layer and carbon layer. The growth way of the coating is island structure. The C/Cr composite coating can improve the corrosion resistance of the magnesium alloy due to the self-corrosion potential is −0.940V. The background vacuum degree is a important factor to improve the corrosion resistance of graphite-like carbon coating, with which being raised, the corrosion resistance become better.