不同锌合金镀层的制备及其耐腐蚀与机械性能研究

Preparation of different zinc alloy coatings and their corrosion resistance and mechanical properties

利用电沉积方法在铜基体上分别制备Zn-Ni合金镀层、Zn-Co合金镀层、Zn-Ni-P合金镀层和Zn-Ni-W合金镀层,并研究不同锌合金镀层的微观形貌、晶相结构、结合强度、耐腐蚀性能、硬度、韧性与耐磨性能。结果表明:不同锌合金镀层完全覆盖铜基体,并且结合强度高,但它们的形貌特征及物相有所不同,耐腐蚀与机械性能也存在差异。Zn-Co合金镀层的晶粒呈团簇颗粒状,堆积紧密;Zn-Ni-P合金镀层的晶粒呈细小块状,堆积紧密;Zn-Ni-W合金镀层的晶粒呈花蕊状,以缠绕形式紧密结合。它们的致密性和耐腐蚀性能明显好于Zn-Ni合金镀层,硬度较Zn-Ni合金镀层分别提高约68 HV、62 HV、109 HV,磨损体积较Zn-Ni合金镀层分别降低约65%、40%、42%。Zn-Ni-P合金镀层的耐腐蚀性能最好,具有最高的电荷转移电阻4.04×103Ω·cm2和低频阻抗模值1.10×104Ω·cm2,而Zn-Ni-W合金镀层具有高硬度(421.8 HV),还表现出良好的韧性与耐磨性能。

Zn-Ni alloy coating,Zn-Co alloy coating,Zn-Ni-P alloy coating and Zn-Ni-W alloy coating were prepared on copper matrix by electrodeposition,and the microstructure,crystal structure,bond‐ing strength,corrosion resistance,hardness,toughness and wear resistance of different zinc alloy coat‐ings were studied.The results show that different zinc alloy coatings completely cover copper matrix and have high bonding strength,but there are differences in the morphology characteristics,phase,cor‐rosion resistance and mechanical properties.The grains of Zn-Co alloy coating are clustered granular and tightly packed,the grains of Zn-Ni-P alloy coating are fine massive and tightly packed,and the grains of Zn-Ni-W alloy coating are stamen and tightly combined in the form of winding.The compact‐ness and corrosion resistance of Zn-Co alloy coating,Zn-Ni-P alloy coating and Zn-Ni-W alloy coating are obviously better than those of Zn-Ni alloy coating.The hardness is about 68 HV,62 HV,109 HV higher than that of Zn-Ni alloy coating,and the wear volume is about 65%,40%,42%lower than that of Zn-Ni alloy coating.Zn-Ni-P alloy coating has the highest charge transfer resistance 4.04×103Ω·cm2 and low-frequency impedance mode value 1.10×104Ω·cm2,showing the best corrosion resistance.How‐ever,Zn-Ni-W alloy coating has the highest hardness of about 421.8 HV,and excellent toughness and wear resistance.