稀土在镁合金钝化中的应用

摘要：本文利用电镀与钝化工艺研究稀土在镁合金表面钝化中的应用。研究了分别添加稀土离子（Pr3+、Ce3+ 、La3+、Y3+、Dy3+、Er3+）浓度、钝化液pH值和时间的改变对钝化膜耐蚀性的影响。用电子能谱仪（EDX）、电子扫描显微镜（SEM）、X射线衍射仪（XRD）对上述钝化膜分别进行表征。研究表明：钝化膜耐蚀性较好的稀土浓度依次为：镨：6.40×10-3 mol/L、铈：0.32×10-3 mol/L、镧：0.32×10-3 mol/L。镝：9.6×10-3 mol/L、钇：8×10-3 mol/L、铒：9.6×10-3 mol/L。点滴实验中各钝化膜耐黑变时间由长到短分别为：镨：65.13s、铈：46.11s、镧：43.39s、镝：36.25s、钇：5.13s、铒：4.75s。pH值在1.5、钝化时间在7.5min时，添加Pr3+离子的钝化膜耐黑变时间达到最大，分别为27.23s、23.37s。
EDX结果表明：钝化膜主要成分有Mg、Al、Cr、O以及稀土元素。XRD结果表明：镁合金经过铬酸盐钝化后表面只形成了Mg的衍射峰，未形成铬酸盐钝化膜的衍射峰。SEM结果表明：稀土离子的添加对钝化膜的微观形貌影响不大。37017
毕业论文关键词：镁合金；钝化；稀土
REE applied in the magnesium alloy surface passivation
Abstract: This article studies the application of rare earth in magnesium alloy surface passivation by using plating passivation technology. Adding rare earth ions was studied respectively (Pr3+、Ce3+ 、La3+、Y3+、Dy3+、Er3+) concentration, passivation solution pH value and the change of time the influence of the corrosion resistance of passivation film. After that，it used electron spectrometer(EDX), scanning electron microscope(SEM), X-Ray Diffraction(XRD) to characterize the passivation layer surface,respectively. The research shows that : the corrosion resistance of the concentration of rare earth added in passivation solution from high to low as follows: Pr：6.40×10-3 mol/L、Ce：0.32×10-3 mol/L、La：0.32×10-3 mol/L。Dy：9.6×10-3 mol/L、Y：8×10-3 mol/L、Er：9.6×10-3 mol/L. In the intravenous drip experiment ,The resistance of passivation time is Pr：65.13s、Ce：46.11s、La：43.39s、Dy：36.25s、Y：5.13s、Er：4.75s，respectively.while the pH value is 1.5 and the passivation time is 7.5min，the resistance of passivation time of the Pr3+ passivation film reached a maximum，it is 27.23s、23.37s respectively.
EDX results showed that the main composition of the passivation film is Mg、Al、Cr、O and rare earth element. XRD results showed that after chromate passivation of magnesium alloy surface only formed the diffraction peak of Mg, it did not form chromate passivation film of diffraction peak. SEM results indicated that: adding rare earth ions has little influence of passivation film morphology.
Keywords: magnesium alloy; passivation; rare earths;
目录
1.前言    1
1.1 研究背景    1
1.2 镁合金表面处理    2
1.2.1 镁合金化学法处理    2
1.2.2 阳极氧化与微弧氧化    3
1.2.3 镁合金有机涂层    4
1.2.4 金属涂层    5
1.3 钝化液配方的组成    6
1.4 稀土元素在金属防腐中的应用    6
1.4.1 稀土的介绍    6
1.4.2 稀土在钝化工艺中的应用    6
1.5 本文研究的内容和意义    7
1.5.1 研究主要内容    7
1.5.2 研究意义    7
2.实验部分    8
2.1 实验材料    8
2.2 实验设备与药品    8
2.2.1 实验设备    8
2.2.2实验药品    8
2.3 钝化液基础组成    9
2.4 稀土离子钝化液的配制    9 稀土在镁合金钝化中的应用:http://www.youerw.com/huaxue/lunwen_35679.html