Enhancing corrosion resistance of MAO coatings on Al alloy LY12 through in situ co-doping with zinc phosphate and cerium phosphate

Corrosion Communications Pub Date : 2025-01-31 DOI:10.1016/j.corcom.2024.10.001

Chao Yang , Tao Ying , Aihui Huang , Jian Huang , Pinghu Chen , Paul K. Chu , Xiaoqin Zeng

{"title":"Enhancing corrosion resistance of MAO coatings on Al alloy LY12 through in situ co-doping with zinc phosphate and cerium phosphate","authors":"Chao Yang , Tao Ying , Aihui Huang , Jian Huang , Pinghu Chen , Paul K. Chu , Xiaoqin Zeng","doi":"10.1016/j.corcom.2024.10.001","DOIUrl":null,"url":null,"abstract":"<div><div>Corrosion of aluminum (Al) alloys during service limits many applications. Micro-arc oxidation (MAO) coatings can enhance corrosion resistance, but porous defects in the films undermine their effectiveness. Here, by mixing a phosphate electrolyte with soluble Zn and Ce salts, zinc phosphate and cerium phosphate co-doped MAO corrosion-resistant coating is prepared on Al alloy LY12. Zinc phosphate and cerium phosphate are incorporated in situ to form an amorphous encapsulated nanocrystalline structure. During long-term corrosion, Zn2+ is released and deposited as corrosion products Zn(OH)2 to cover weak corrosion micro-regions in the coating. Simultaneously, Ce3+ released from MAO coating co-doped with zinc phosphate/cerium phosphate forms Zn(OH)2/Ce(OH)3 due to the small solubility product Ksp to further enhance corrosion resistance. Compared to pristine Al alloy, corrosion potential increases from -1.306 to -0.819 VSCE, and corrosion current density decreases by 4 orders of magnitude from 2.6 × 10−6 to 2.5 × 10−10 A·cm−2. Co-doped MAO coating significantly enhances corrosion resistance of Al alloy LY12 and shows great potential for a wide range of applications.</div></div>","PeriodicalId":100337,"journal":{"name":"Corrosion Communications","volume":"17 ","pages":"Pages 35-43"},"PeriodicalIF":0.0000,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Corrosion Communications","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2667266925000064","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 0

Abstract

Corrosion of aluminum (Al) alloys during service limits many applications. Micro-arc oxidation (MAO) coatings can enhance corrosion resistance, but porous defects in the films undermine their effectiveness. Here, by mixing a phosphate electrolyte with soluble Zn and Ce salts, zinc phosphate and cerium phosphate co-doped MAO corrosion-resistant coating is prepared on Al alloy LY12. Zinc phosphate and cerium phosphate are incorporated in situ to form an amorphous encapsulated nanocrystalline structure. During long-term corrosion, Zn²⁺ is released and deposited as corrosion products Zn(OH)₂ to cover weak corrosion micro-regions in the coating. Simultaneously, Ce³⁺ released from MAO coating co-doped with zinc phosphate/cerium phosphate forms Zn(OH)₂/Ce(OH)₃ due to the small solubility product K_sp to further enhance corrosion resistance. Compared to pristine Al alloy, corrosion potential increases from -1.306 to -0.819 V_SCE, and corrosion current density decreases by 4 orders of magnitude from 2.6 × 10⁻⁶ to 2.5 × 10⁻¹⁰ A·cm⁻². Co-doped MAO coating significantly enhances corrosion resistance of Al alloy LY12 and shows great potential for a wide range of applications.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Corrosion Communications

CiteScore

7.30

自引率

0.00%

发文量