锌镍合金镀层耐腐蚀性的研究

Corrosion Resistance of Zinc Nickel Alloy Plating

锌镍合金层具有优异的耐蚀性,从全硫酸盐体系中用电沉积的方法制备了纯锌镀层和锌镍合金镀层。应用能量色散X射线分析仪检测了合金层的相对含量。通过中性盐雾试验、极化曲线、交流阻抗和腐蚀浸泡等试验方法研究了镀层的耐腐蚀性能。试验表明,含镍 16%的锌镍合金镀层的腐蚀电位较纯锌镀层的腐蚀电位正移 230mV,该合金的耐盐雾性能达到 1 000h,是相同厚度纯锌镀层的 4. 5倍,具有优良的耐腐蚀性。

Zinc plating and (zinc )nickel (16%) alloy plating were prepared on ferrous substrate by electrodepositing in a sulfate bath. The composition of the Zn Ni alloy plating was determined using energy dispersive X ray analysis. The corrosion resistance of the plating was investigated by neutral salt spray (NSS) test, potentiodynamic polarization curve, AC impedance technique, and immersion corrosion test. It was found that the corrosion potential of the Zn Ni alloy plating had a positive shift by 230 mV as compared with that of the pure Zn plating. At the same time, the Zn Ni (16%) alloy plating had excellent corrosion resistance. Namely, the Zn Ni alloy plating had a salt spray resistance of 1 000 h, which was 4.5 times as much as that of the pure Zn plating with the same thickness.