室温离子液体中电沉积高耐蚀性Ni-Mn薄膜  

Electrodeposition of Ni-Mn Films of High Corrosion Resistance at Room Temperature in Ionic Liquids

作　　者：章志铖 郭嘉成 徐文彬[1] 聂乐文 弓磊超 郭兴伍[1] 丁文江[1] 

机构地区：[1]上海交通大学轻合金精密成型国家工程研究中心,上海200240

出　　处：《表面技术》2017年第3期66-71,共6页Surface Technology

基　　金：国家自然科学基金项目(51371116);航天先进技术联合研究中心技术创新项目(USCAST2013-23);江苏省科技成果转化项目(BA2016039)~~

摘　　要：目的提高AZ91D镁合金的耐腐蚀性能。方法通过电沉积方法在氯化胆碱-尿素离子液体中于镁合金表面电沉积Ni-Mn合金膜层。经过均一化前处理,在镁合金表面电沉积铜层,以提高后续Ni-Mn合金膜层与基体的结合力。利用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)研究了Mn元素对膜层微观形貌、成分和相结构的影响,并通过电化学方法评价了镀层的电化学腐蚀行为。结果引入Mn元素后,膜层表面微观形貌从锥状演变为肿瘤状,且Ni-Mn合金膜层的Mn含量取决于电流密度,其含量随着电流密度的增加而增加。与纯Ni膜相比,引入少量Mn元素可以提高其耐腐蚀性能,然而引入过多的Mn元素,膜层的耐腐蚀性能将弱于纯Ni膜。结论当电沉积Ni-Mn膜层含有3.078%(原子数分数)Mn时,具有最佳的耐腐蚀性能,其自腐蚀电流密度Jcorr=0.301μA/cm2,自腐蚀电位Ecorr=-0.157 V(vs.SCE)。The work aims to improve corrosion resistance of AZ91 D magnesium alloy.Ni-Mn alloy film was electrodeposited on the surface of magnesium alloy in the choline chloride-urea ionic liquid by electrodeposition method.After homogenization pretreatment,the copper layer was electrodeposited on the surface of magnesium alloy to improve the adhesion between subsequent Ni-Mn alloy film and the substrate.The effects of Mn element on the surface morphology,chemical composition and phase structure of the film were studied by using scanning electronic microscopy（SEM）,energy-dispersive X-ray spectroscopy（EDS） and X-ray diffraction spectroscopy（XRD）.Once Mn was incorporated into the film,the surface morphology transformed from pyramid-like to tumor-like clusters.Moreover,Mn content of Ni-Mn alloy film rest on current density and increased as the current density increased.Corrosion resistance of the coating could be improved by introducing a little Mn com-pared with pure Ni film.However,the corrosion resistance of the film was weaker than that of the pure Ni film when too much Mn was introduced.The Ni-Mn alloy film,when containing 3.078 at.% Mn,shows the best corrosion resistance with self-corrosion current Jcorr of 0.301 μA/cm^2 and corrosion potential Ecorr of-0.157 V（vs.SCE）.

关 键 词：镁合金 离子液体 Ni-Mn合金膜 微观形貌 腐蚀防护 

分 类 号：TG174.441[金属学及工艺—金属表面处理]