氯化胆碱-尿素中三元合金膜的制备及耐腐蚀性表征  

Preparation and corrosion resistance characterization of ternary alloy film in choline ChCl-urea

作　　者：杜婵 陈必清 高利霞 熊彤彤 朱云娜 张士民 DU Chan;CHEN Biqing;GAO Lixia;XIONG Tongtong;ZHU Yunna;ZHANG Shimin(School of Chemistry and Chemical Engineering,Qinghai Normal University,Qinghai 810000,China)

机构地区：[1]青海师范大学化学化工学院

出　　处：《功能材料》2019年第10期10178-10185,共8页Journal of Functional Materials

基　　金：青海基础研究计划资助项目(2016-ZJ-753);国家自然科学基金资助项目(21553002)

摘　　要：探究ChCl-urea低共熔溶剂对电沉积合金膜含量的影响,并提升二元镁合金的耐腐蚀性能。在353K的ChCl-urea低共熔溶剂中,利用恒电位电解法制备了Eu-Mg-Co合金膜对Mg合金组成及耐腐蚀性进行优化。利用循环伏安法研究ChCl-urea以及加入金属元素后熔体的电化学行为。在Pt电极上的循环伏安曲线表明,Co(Ⅱ)+2e→Co(0)是一步不可逆反应,并计算得出Co(Ⅱ)在Pt电极上的传递系数α以及扩散系数D0[1]。稀土元素Eu和金属Mg沉积电位较负,难以单独沉积得到单一元素的合金膜,但能在Co(Ⅱ)的作用下诱导共沉积得到多元合金膜。在不同电位和不同组成的镀液中采用恒电位计时电流法进行电沉积,用EDS分析和SEM对合金膜进行分析和表征。对合金膜进行Tafel测试,利用外推法得出合金膜在NaCl溶液中的自腐蚀电流与电位。Co(Ⅱ)在Pt电极上的传递系数α=0.093,扩散系数D0=1.177×10^-5cm^2/s。EDS结果表明在沉积电位-1.18V,镀液配比为0.04mol/LCoCl2+0.04mol/LMgCl2+0.03mol/LEu(NO3)3时合金膜中Eu含量最高,Eu-Mg-Co有良好的耐腐蚀性。结论:得到镀层晶粒细致均匀的Eu-Mg-Co合金膜,加入稀土Eu元素的三元合金膜耐腐蚀性能优于Co-Mg二元合金膜。To investigate the effect of ChCl-urea eutectic solvent on the content of electrodeposited alloy film and improve the corrosion resistance of binary magnesium alloy,the Eu-Mg-Co alloy film was prepared by constant potential electrolysis in a 353 K ChCl-urea eutectic solvent to optimize the composition and corrosion resistance of Mg alloy.Cyclic voltammetry was used to study the electrochemical behavior of ChCl-urea and the addition of metal elements.The cyclic voltammetry curve on the Pt electrode shows that Co(Ⅱ)+2e→Co(0) was a one-step irreversible reaction,and the transfer coefficient α of Co(Ⅱ) on the Pt electrode and the diffusion coefficient D0 were calculated.The rare earth element Eu and the metal Mg had a relatively low deposition potential,and it was difficult to separately deposit a single element alloy film,but a co-deposition could be induced by Co(Ⅱ) to obtain a multi-alloy film.The electrodeposition was performed by potentiostatic chronoamperometry in different potentials and different compositions.The alloy film was analyzed and characterized by EDS analysis and SEM.The alloy film was subjected to Tafel test,and the self-corrosion current and potential of the alloy film in NaCl solution were obtained by extrapolation.The results show that the transfer coefficient of Co(Ⅱ) on the Pt electrode was α=0.093,and the diffusion coefficient D0 was 1.177×10^-5 cm^2 /s.The EDS results show that the Eu content was the highest in the alloy film when the deposition potential was -1.18 V and the plating solution ratio was 0.04 mol/L CoCl2 +0.04 mol/L MgCl2 +0.03 mol/L Eu(NO3 ) 3.Eu-Mg-Co had good corrosion resistance.The Eu-Mg-Co alloy film with fine and uniform coating grain was obtained.The corrosion resistance of the ternary alloy film with rare earth Eu element was better than that of Co-Mg binary alloy film.

关 键 词：电化学行为 不可逆反应 诱导共沉积 恒电位法 稀土合金膜 耐腐蚀性 

分 类 号：O646[理学—物理化学] O645[理学—化学]