摘要镁合金因其具有良好的导电导热性、比强度高、优良的磁屏蔽性和机械加工性能， 广泛应用于各工业领域，但其耐腐蚀性差的特点制约了它的发展及其更广泛的应用。化 学镀层技术在防腐领域起着重要的作用。81103

本文主要研究了 AZ91D 镁合金化学镀的方法及性能，通过直接对镁合金进行化学 镀来提高镁合金的耐蚀性。实验主要在草酸，柠檬酸，酒石酸三种酸洗液中，通过对比 试验选择出最优的酸洗液，结果表明 AZ91D 镁合金用草酸酸洗 40s 的效果最好。在预 浸镀溶液配方上经过对比以及实验的改进，选择出乙酸镍和乳酸的混合溶液作为最优预 浸镀方案。采用 XRD,EDS,SEM 对试样 Ni-P 镀层的元素成分的组成和含量进行了分析 与测定，结果表明，用柠檬酸做预浸镀溶液时，Ni-P 最开始的沉积会在氧化镁处，将柠 檬酸替换成乳酸效果将得到提高。通过电化学试验的检测得出了 Ni-P 镀层能提高镁合 金的耐蚀性的结论，以便镁合金能够投入到更多的行业领域中。

毕业论文关键词：AZ91D 镁合金；化学镀；Ni-P 镀层

Abstract Magnesium alloys have excellent electrical and thermal conductivity, high strength, terrific magnetic shielding and mechanical processing performance。It has been widely used in various industrial fields, but the poor corrosion resistance characteristics restrict its develop- ment and wider use。Chemical coating technology plays an important role in the field of anti-corruption。

This paper studies the methods and properties of AZ91D magnesium alloy plating,we used magnesium alloy plating to improve corrosion resistance。This test is mainly about oxalic acid, citric acid and tartaric acid,and we found out that the best method is that AZ91D magnesium alloy mixed with oxalic acid picked for 40s tuning out the best。Through continuous improvement and the comparison test,we chose out of a mixed solution of nickel acetate and lactate as an experimental program prepreg plating。We also used XRD,  EDS, SEM sample composition and content of Ni-P plating elemental composition to analyse and measure the results。It showed that when we used the presoaked with citric acid to make a solution。If we replace the deposition of the beginning of the Ni-P with magnesium oxide, the citric acid effect will be improved。Additionally,we detected that obtained Ni-P plating can improve corrosion resistance of magnesium alloy original conclusions through an electrochemical test , so we can devote more of magnesium alloy to apply to industry fields。

Key words : AZ91D magnesium alloy ; chemical plating ;Ni-P plating

目录

第一章 绪论 1

1。1 镁合金的特点 1

1。2 镁合金的应用 1

1。3 镁合金的腐蚀 2

1。4 镁合金的腐蚀防护 3

1。5 化学镀 5

1。5。1 化学镀镍的原理 5

1。5。2 镁合金化学镀镍工艺特点 6

1。6 镀膜的检测方法 7

1。7 化学镀原理及现状 8

1。7。1 化学镀原理 8

1。7。2 化学镀研究现状 8

1。8 研究的目的与意义 8

1。9 实验内容 9

第二章 实验材料及其方法 10

2。1 实验材料