镁合金电镀镍涂层的耐蚀性能

以化学镀镍作为保护层,对AZ91D镁合金进行直流电镀镍涂层以提高其耐腐蚀性能,并对镁合金表面两个不同厚度的镀镍涂层进行了比较.采用SEM对涂层的表面形态进行了研究.在X射线下纹理明显.镍涂层硬度约560VHN,远远高于AZ91D镁合金基底的硬度(约100VHN).电化学测量结果表明,在已经研究的镁合金涂层中,镍镀层有最低的腐蚀电流密度和最高的腐蚀电位.加速腐蚀实验中AZ91D镁合金镀镍具有很高的耐腐蚀性能.

Corrosion-resistance of electroplated nicked coating on magnesium alloy

Ni coating was direct-current electrodeposited on the AZ91D magnesium alloy substrate aimed to improve its corrosion resistance using a direct electroless plating of nickel as the protective layer. As comparison, two electroless Ni coatings on the magnesium alloy with different thickness were also presented in the paper. The surface morphologies of the coatings were studied by SEM . The hardness of the Ni coating was about 560 VHN,which was far higher than that （about 100 VHN） of the AZ91D Mg alloy substrate. The electrochemical measurements showed that the nc Ni coating on the magnesium alloy had the lowest corrosion current density and most positive corrosion potential among the studied coatings on the Mg alloy. The Ni coating on the AZ91D Mg alloy exhibited very high corrosion resistance in the rapid corrosion test illustrated in the paper.