Preparation and Properties of Ni-W Alloy Coating on Surface of Magnesium Alloy

Ni-W alloy coatings were prepared on the surface of magnesium alloy using electroplating method. The effects of Na₂WO₄ concentration and current density during the electroplating process on the microstructure and properties of the coatings were studied respectively, through electron scanning microscopy (SEM), X-ray diffraction (XRD), hardness testing and electrochemical testing. The results show that when the current density was constant, with the increase of sodium tungstate concentration, the hardness and porosity increased, but the corrosion resistance decreased for the coating. At the same sodium tungstate concentration, the hardness and pitting potential increased with the increase of current density, while the corrosion resistance changed slightly for the coating. When the current density was 2 A/dm² and the concentration of sodium tungstate was 10 g/L, the prepared coating had high hardness and high corrosion resistance.