电沉积电位对锌镍合金镀层耐蚀性的影响

Effect of electrodeposition potential on corrosion resistance of Zn-Ni alloy coatings

采用电化学沉积方法在DH36船板钢表面制备了锌镍合金镀层。采用扫描电镜(SEM),能谱仪(EDS)和X射线衍射仪(XRD)等研究了电化学沉积电位对锌镍合金镀层形貌、化学成分和晶体结构的影响。结果表明:随着沉积电位的升高,锌镍合金镀层由无法覆盖整个基底表面到均匀致密覆盖,再到较大微纳米颗粒层覆盖,证明沉积速率越来越大。由EDS和XRD分析可知,在较低电位下沉积,锌镍电沉积过程属于正常共沉积,而在较高电位沉积时,锌镍电沉积过程属于异常共沉积。电化学极化曲线测试表明,在电沉积电位为-1.2 V时所获得的锌镍合金镀层的耐腐蚀性最好。

The zinc-nickel alloy coatings were prepared on the surface of DH36 hull plate by an electrochemical deposition method. The effects of electrochemical deposition potential on morphology, chemical composition and crystal structure of the zinc-nickel alloy coatings were studied by means of scanning electron microscopy(SEM), energy dispersive spectrometer(EDS) analysis and X-ray diffractometer(XRD). The results show that, with the increase of the electrodeposition potential, the zinc-nickel alloy coatings first can not cover the whole surface of the substrate then to the uniform and compact cover, last to the larger micro-nano-particle layer to cover, which show that the deposition rate is more and more large. It is known from the analysis of EDS and XRD that the zinc-nickel electrodeposition process belongs to the normal co-electrodeposition at the lower electrodeposition potential, and the zinc-nickel electrodeposition process belongs to the abnormal co-electrodeposition at the time of higher electrodeposition potential. The electrochemical polarization curve test results show that the corrosion resistance of the zinc-nickel alloy coating obtained when the electrodeposition potential is-1.2 V is the best.