论文总字数：19901字

摘 要

sp2复合镀层的方法，来改善这些缺点。通过电化学工作站测量不同厚度的MAO涂层腐蚀电流密度，通过腐蚀电流密度的大小来表征镀层表面的耐蚀性。通过四探针法测量不同厚度的MAO涂层的接触电阻，通过接触电阻来表征镀层表面的导电性。通过控制MAO制备时间来表征MAO涂层的厚度，从而研究不同MAO厚度下镀层表面的耐蚀性和导电性。实验结果表明：随着镀膜时间的增加，在时间由2min增加到6min，MAO镀层厚度呈现增长趋势，特别地，当时间由2min增长到4min时，镀层厚度增长速度较缓慢，当时间由4min增长到6min时时，镀层厚度增长十分迅速，当时间由6min增长到8min时，镀层厚度缓慢减小，厚度变化幅度非常小。

随着镀膜时间的增加，在2min到6min镀膜粗糙度增加，增长幅度较稳定，6min以后镀膜粗糙度减小，厚度变化幅度非常小。

在MAO涂层制备时间分别为2min、4min、6min、8min和纯铝的设置对照组中，通过电化学工作站以及塔菲尔曲线测得当MAO涂层制备时间为2min时，镀层表面的接触电阻最低，最低为0.64Ω·cm²，从而得出结论，在MAO涂层制备时间为2min时，镀层表面的导电性最好。

在MAO涂层制备时间分别为2min、4min、6min、8min和纯铝的设置对照组中，通过四探针法测得当MAO涂层制备时间6min时，镀层表面的腐蚀电流密度最低，最低为3.31×10^-3A/cm²，从而得出结论，在MAO涂层制备时间6min时，镀层表面的耐蚀性最好。

关键词：磁控溅射 MAO/C^sp2复合镀层 接触电阻 腐蚀电流密度

Study on corrosion resistance and conductivity of Al based MAO/C^sp2 composite coatings

ABSTRACT

This topic according to the traditional aluminum substrate as a bipolar plate for fuel cell of corrosion resistance of low, plate and gas diffusion layer of the contact resistance value is proposed through the aluminum substrate surface plating on MAO(Microarc oxidation)/C^sp2 composite coating method to improve these disadvantages. By electrochemical work station measurements of different thickness of the MAO coating corrosion current density and by the size of the corrosion current density to characterization on the surface of the coating corrosion resistance. By four probe method for measuring different thickness of the MAO coating contact resistance. Through the contact resistance to characterize the coating surface conductivity. By control Mao preparation time characterization of the MAO coating thickness. The corrosion resistance and conductivity of the coating surface under different MAO thickness were studied:

With the increase of coating time and in time by 2 min increased to 6 minutes, the MAO coating thickness showed growth trend, especially, when the time is 2min growth to 4min, coating thickness growth speed is slow, when time is 4min growth to 6min always, coating thickness is growing very fast, when time is 6min growth to 8 minutes, coating thickness decreases slowly, thickness variation amplitude is very small.

With the increase of coating time, the 2min to 6min coating roughness increases, the growth rate is relatively stable, 6min coating roughness decreases, thickness change is very small.

In the MAO coating preparation time respectively for 2min, 4min, 6min, 8min and pure aluminum set in the control group, by the electrochemical workstation and Tafel curves measured properly the MAO coating preparation time was 2min, contact resistance of the coating on the surface of the lowest, and the lowest was 0.64 OMEGA / cm², thus draws the conclusion, in the MAO coating preparation time was 2min, on the surface of the coating has the best conductivity.

In the MAO coating preparation time respectively for 2min, 4min, 6min, 8min and pure aluminum set in the control group, by the four probe method measured properly the MAO coating preparation time was 6 min, surface coating corrosion current density is lowest, and the lowest was 3.31 × 10^-3A/cm², thus obtains conclusion, in the MAO coating preparation time 6min, coating on the surface of the best corrosion resistance.

Key Words: magnetron sputtering; MAO/C^sp2 composite coating; contact resistance; corrosion current density

目 录

摘要 I

ABSTRACT II

第一章 文献综述 1

1.1 前言 1

1.2 铝合金表面处理技术的介绍 1

1.3 微弧氧化 2

1.3.1 微弧氧化的原理 2

1.3.2 微弧氧化的特点 2

1.3.3 微弧氧化的应用 3

1.4 磁控溅射技术 3

1.4.1 磁控溅射技术简介 3

1.4.2 磁控溅射的原理 4

1.4.3 磁控溅射的的设备及工艺 4

1.5 课题的研究目的及意义 5

第二章 实验 6

2.1 实验原料及前处理 6

2.1.1 实验基材 6

2.1.2 镀膜前预处理 6

2.2 实验设备 6

2.3 MAO/C^sp2复合镀层的制备 7

2.4 MAO/C^sp2复合镀层表征分析方法与原理 8

2.4.1 形貌分析 8

2.4.2 MAO厚度测试 8

2.4.3 MAO粗糙度测试 9

2.4.4 接触电阻测试 9

2.4.5 耐蚀性测试 10

第三章 实验结果分析与讨论 12

3.1 MAO/C^sp2复合镀层微观结构 12

3.1.1 MAO及C^sp2镀层厚度变化规律 12

3.1.2 镀层厚度变化原理 13

3.1.3 MAO及C^sp2镀层表面粗糙程度变化规律 13

3.1.4 镀层粗糙度变化原理 14

3.1.5 MAO/C^sp2镀层表面及截面形貌 15

3.2 MAO/C^sp2复合镀层的表面接触电阻测试 16

3.3 MAO/C^sp2复合镀层的耐蚀性能分析 17

3.3.1 动电位极化曲线测试 17

3.3.2 腐蚀后镀层表面形貌 19

第四章 结论 21

参考文献 22

致谢 24

第一章 文献综述

1.1 前言

能源短缺、大气污染等问题，是全球汽车产业共同面临的巨大挑战。2011年全球53%的石油消费在交通领域^[1]，目前世界汽车保有量约7亿辆。交通的能源消耗已经成为引起环境污染和有害气体排放的主要来源之一，能源转型势在必行。新能源是替代汽、柴油等的清洁能源，效率高、环境好、排放低，镍氢、锂电和燃料电池等新能源汽车电池作为现今提供汽车能量的主要清洁能源，在新能源汽车上被运用。新能源汽车电池环保节能、高效安全，并脱离石油产能瓶颈的约束^[2]。许多国家政府、科研机构和企业高度重视，进行了相关技术的研发。由于氢能是清洁无污染的新能源，因此氢燃料电池成了新的研究对象。双极板是氢燃料电池的核心组成部分，一般的石墨双极板体积过大，占用太大空间，使用起来要求比较高，金属双极板有着高导热高导电性，机械性能也相当不错，但堆叠而成的电堆质量偏大^[3]。而铝合金双极板可以使电池缩尺减重，但存在耐蚀性能较差的缺点，因此必须对其表面进行处理，形成防护层^[4]。表面改性是在物体表面覆盖涂层，来增强物体表面的物理性能。

1.2 铝合金表面处理技术的介绍

铝合金材料经过表面处理后，性能能够得到改善、质量得以提升。由于工业应用对铝合金的表面性能的需求非常之多，使得铝合金的表面处理技术经历了长足而多元性的变迁^[4]。铝材有多种表面处理方法，不同的方法为铝材表面带来了不同的物理性能。其中较为具有代表性的处理如下：

1. 阳极氧化：在铝板表面生成不导电的氧化膜，能过有效提高防护性能。但是由于氧化膜不导电，在一些需要导电的情况下不不能使用此方法。
2. 2.阳极氧化后着色：在氧化膜上生成想要的颜色，来满足具体的使用需求。

3.导电氧化（铬酸盐转化膜）：用于既要防护又要导电的场合。

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