论文总字数：19459字

摘 要

本文采用磁控溅射方法于6061铝合金表面制备了一系列银掺杂类石墨涂层，研究了类石墨涂层中银的自发逸出行为及其抑制机制。通过扫描隧道显微镜、能谱仪及四探针测试仪等对样品微观形貌、成分及接触电阻进行了表征。研究结果表明，涂层沉积结束后，从真空腔中取出放置于大气环境中30min即可观察到明显的银逸出现象；随着银靶电流密度的增大，银于类石墨涂层中的逸出现象越来越明显，当银靶电流为0.05A时，在表面形成一层厚度约为150nm的金属银层；表面覆盖纯碳涂层能够有效抑制银的逸出，当表面碳覆盖层厚度达到700nm时，基本可实现银于非晶类石墨涂层中的永久滞留。Ag掺杂镀膜样品的耐腐蚀性能相比未掺杂样品普遍有所提高，随着类石墨涂层中的银掺杂量由2.27 at.%增加至5.35 at.%，涂层的接触电阻降低了一个数量级（由51 mΩ·cm²降低至6 mΩ·cm²）。其中，Ag靶电流为0.04A时制得的碳膜样品腐蚀电流密度达到最低，为1.10×10^-6A·cm^-2，相比未掺杂碳膜腐蚀电流密度（9.35×10^-3A·cm^-2）下降2个数量级。

关键词 :非晶类石墨碳 银 逸出机理 抑制途径

Escape mechanism and inhibition pathway of silver in amorphous graphite carbon coating

Abstract

In this paper， a series of silver-doped graphite coatings were prepared on the surface of 6061 aluminum alloy by magnetron sputtering method. The spontaneous escape behavior of silver in the graphite-like coating was studied and its inhibition mechanism was studied. The microscopic morphology， composition and contact resistance of the samples were characterized by scanning tunneling microscopy， energy dispersive spectrometer and four - probe tester. The results show that the silver removal phenomenon can be observed in the atmosphere for 30 min after removal of the coating. With the increase of the silver target current density， the silver is in the graphite-like coating As the silver target current is 0.05A， then there will form a silver layer which is about 150nm . The surface covered with pure carbon coating can effectively inhibit the escape of silver. When the surface carbon coating When the thickness reaches 700 nm， the permanent retention of silver in the amorphous graphite coating can be basically achieved.The corrosion resistance of the Ag-doped coating sample is generally higher than that of the undoped sample. As the amount of silver in the graphite-like coating increases from 2.27 at.% To 5.35 at.%， The contact resistance of the coating decreases An order of magnitude (reduced from 51 mΩ · cm^-2 to 6 mΩ · cm^-2). The corrosion current density of the carbon film sample was 1.10 × 10^-6A · cm^-2 when the Ag target current was 0.04A， which was lower than that of the undoped carbon film (9.35 × 10^-3A · cm ^-2) decreased by 2 orders of magnitude.

Key Words: amorphous graphite carbon;silver;escape mechanism;inhibition pathway

目录

摘要 I

Abstract II

第一章 引言 1

1.1质子交换膜燃料电池 1

1.2石墨双极板 2

1.3金属双极板 2

1.4薄膜制备技术 4

1.4.1化学气相沉积 4

1.4.2电弧离子镀 4

1.4.3磁控溅射离子镀 5

1.5薄膜改性金属双极板的研究进展 7

1.5.1金属氮化物薄膜 7

1.5.2碳基薄膜 8

第二章 实验 9

2.1 实验的主要内容及目的 9

2.2 实验材料及设备 9

2.2.1 实验仪器简介 9

2.2.2 样品基片及预处理 10

2.2.2实验设计 11

第三章 银于非晶石墨碳涂层的自发逸出行为及抑制方法 13

3.1 Ag于类石墨碳涂层中的自发逸出行为 13

3.1.1 Ag掺杂对类石墨薄膜微观结构影响 13

3.1.2掺银镀层内部银残留及外层银含量测定 16

3.1.3银自发逸出机理的讨论 18

3.2 Ag掺杂对类石墨碳膜导电能力的影响 19

3.3 Ag掺杂对类石墨碳膜耐腐蚀性能的影响 20

3.4覆盖类石墨涂层抑制银的逸出 21

3.5 本章小结 22

第四章 结论 24

参考文献 25

1. 引言

1.1质子交换膜燃料电池

质子交换膜燃料电池（Proton Exchange Membrane Fuel Cell，PEMFC）是以全氟磺酸型离子交换膜作为电解质、金属铂和活性炭为催化剂的一种氢电池，其燃料和氧化剂与普通氢电池类似。由于其能量转化效率高、清洁、安全等优点^[1-6]，受到了世界上许多有研发能力的组织热捧^,[1]。

图1-1质子交换膜燃料电池结构示意图

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