微弧氧化及封孔处理对铸造Al - Cu - Mg - Ag合金耐腐蚀性能的影响

曾娣平, 刘志义, 吴海江, 郭文敏, 陈东瑞

doi:10.16577/j.issn.1001-1560.2022.0224

材料保护 >

2022 , Vol. 55 >Issue 8: 117 - 124

DOI: https://doi.org/10.16577/j.issn.1001-1560.2022.0224

工艺探讨

微弧氧化及封孔处理对铸造Al - Cu - Mg - Ag合金耐腐蚀性能的影响

展开

(1. 邵阳学院机械与能源工程学院，湖南邵阳 422000；2. 中南大学材料科学与工程学院，湖南长沙 410083)

刘志义(1962-)，教授，博士，主要研究方向为铝合金、镁合金及陶瓷材料，电话：0731-888366011，E - mail:liuzhiyi@csu.edu.cn

收稿日期: 2022-02-22

修回日期: 2022-03-31

录用日期: 2022-04-26

网络出版日期: 2023-12-17

基金资助

湖南省教育厅科学研究青年项目(21B0674)资助；湖南省教育厅资助科研项目(20K112)

收起

Effect of Micro - Arc Oxidation and Sealing Treatment on the Corrosion Resistance of Cast Al - Cu - Mg - Ag Alloy

Expand

(1. School of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422000, China;2. School of Materials Science and Engineering, Central South University, Changsha 410083, China)

Received date: 2022-02-22

Revised date: 2022-03-31

Accepted date: 2022-04-26

Online published: 2023-12-17

Fold

摘要

为了增强铸造Al - Cu - Mg - Ag合金的耐腐蚀性能，在合金表面制备了微弧氧化(MAO)涂层，并通过有机硅环氧树脂对MAO涂层进行了封孔处理。通过电化学测试、盐雾实验和全浸实验分析了封孔处理前后Al - MAO涂层体系的耐腐蚀性能。结果显示：铸造Al - Cu - Mg - Ag合金经过腐蚀实验后，发生了严重的腐蚀，沿晶界出现了大量的腐蚀深坑，抗拉强度下降了约60 MPa；Al - MAO涂层在腐蚀实验后，腐蚀介质通过MAO涂层表面的微孔腐蚀合金基底，在表面出现了大量白色点状的腐蚀产物，其抗拉强度下降了约25 MPa；封孔处理后的Al - MAO涂层与Al - MAO涂层相比，腐蚀电流密度从2.62×10-8 A/cm2降低到5.52×10-12 A/cm2，腐蚀电位从-589 mV正移到-342 mV，低频阻抗值从～105 Ω·cm2增加到～109 Ω·cm2，并且在盐雾实验和全浸实验后，没有发生任何腐蚀现象，抗拉强度基本保持不变。用有机硅环氧树脂对MAO涂层体系进行封孔处理后，MAO涂层的表面缺陷被封闭，在合金表面形成了致密的陶瓷 - 有机复合涂层，极大地降低了腐蚀速率，显著提高了合金体系的耐腐蚀性能。

关键词： 微弧氧化; 封孔处理; 电化学测试; 抗拉强度; 耐腐蚀性

本文引用格式

曾娣平, 刘志义, 吴海江, 郭文敏, 陈东瑞 . 微弧氧化及封孔处理对铸造Al - Cu - Mg - Ag合金耐腐蚀性能的影响[J]. 材料保护, 2022 , 55(8) : 117 -124 . DOI: 10.16577/j.issn.1001-1560.2022.0224

Abstract

In order to enhance the corrosion resistance of the cast Al - Cu - Mg - Ag alloy, a micro - arc oxidation (MAO) coating was prepared on the surface of the alloy and then sealed with silicone epoxy resin. The corrosion resistance of the Al - MAO coating system before and after sealing treatment was analyzed by electrochemical test, salt spray test and full immersion test. Results showed that after the corrosion test, the cast Al - Cu - Mg - Ag alloy corroded seriously, a large number of corrosion pits appeared along the grain boundary, and the tensile strength of alloy decreased by about 60 MPa; as for the Al - MAO coating system, the corrosion medium corroded the alloy substrate through the micro pores on the surface of the coating, a large number of white spot - like corrosion products appeared on the surface, and its tensile strength decreased by about 25 MPa. The effects of sealing treatment on the Al - MAO coating were as follows: the corrosion current density reduced from 2.62×10-8A/cm2 to 5.52×10-12A/cm2; the corrosion potential positively shifted from -589 mV to -342 mV; the low - frequency impedance increased from～105 Ω·cm2 to ～109 Ω·cm2; after the salt spray test and the full immersion test, no corrosion occurred; and the tensile strength basically remained the same. After the sealing treatment, the surface defects of the MAO coating were sealed, and a dense ceramic - organic composite coating formed on the alloy surface, which greatly reduced the corrosion rate and significantly improved the corrosion resistance of the alloy system.

Key words： micro - arc oxidation; sealing treatment; electrochemical test; tensile strength; corrosion resistance

Options

文章导航

模态框（Modal）标题

摘要

本文引用格式

Abstract