Preparation and Properties of Nano-ceramic TiO₂/Ni Composite Electroplating on Magnesium Alloy

A kind of nano-TiO2/Ni composite coating was successfully prepared on magnesium alloy surface by the method of pre-chemical nickel plating and composite electroplating.The corrosion resistance of the composite coating was investigated by the method of NaCl solution immersion and polarization curves.The plating speed of the composite electroplating was 26 μm/h.The composite coating was compact,homogeneous and had good cohesion with the substrate.The hardness of the composite coating is higher than that of both magnesium alloy substrate and nickel coating.No corrosion appeared on composite coating surface after 120 h immersion in 3.5% NaCl solution.The results of polarization curves showed that the composite coating could improve the corrosion resistance of Mg alloy obviously.