Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatment
The microstructure and corrosion processes of a friction stir welded (FSW) 7075-T6 aluminum alloy joint, before and after anodizing surface treatment, have been characterized by advanced techniques, and the feasibility of anodizing treatment as a corrosion mitigation method has been evaluated. The r...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | Materials Research Express |
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| Online Access: | https://doi.org/10.1088/2053-1591/aca007 |
| _version_ | 1797746234252853248 |
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| author | Kai Li Hong Yang Mengting Zou Bingyuan Yang Huibin Xu Huaxia Zhao Henggang Yin Yanlong Ma |
| author_facet | Kai Li Hong Yang Mengting Zou Bingyuan Yang Huibin Xu Huaxia Zhao Henggang Yin Yanlong Ma |
| author_sort | Kai Li |
| collection | DOAJ |
| description | The microstructure and corrosion processes of a friction stir welded (FSW) 7075-T6 aluminum alloy joint, before and after anodizing surface treatment, have been characterized by advanced techniques, and the feasibility of anodizing treatment as a corrosion mitigation method has been evaluated. The results showed that different zones of the FSW joint had distinctly different microstructure and consequently different corrosion behavior in NaCl solution. Stable localized corrosion occurred in the transitional regions between the thermo-mechanically affected zone (TMAZ) and heat affected zone (HAZ), and was characterized by intergranular corrosion. The intergranular corrosion was ascribed to the galvanic coupling effect between Cu-rich grain boundary precipitates and the precipitates free zones (PFZs). Although anodizing and the subsequent sealing treatments could greatly improve the corrosion resistance of the base metal, the TMAZ/HAZ transition regions still showed much higher corrosion susceptibility than other regions. The high corrosion susceptibility of the FSW joint after anodizing treatment is not ascribed to the difference of the anodic oxide film in the regions, but the heterogeneous microstructure of the alloy beneath the anodic film. The present paper has shown that the stable localized corrosion in the FSW joint is intrinsically stemmed from the welding process itself and traditional mitigation method such as anodizing treatment cannot solve the problem; more effective corrosion mitigation methods are still awaited. |
| first_indexed | 2024-03-12T15:34:57Z |
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| id | doaj.art-fdf38d8e17774b50b45e7daf0829c231 |
| institution | Directory Open Access Journal |
| issn | 2053-1591 |
| language | English |
| last_indexed | 2024-03-12T15:34:57Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
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| series | Materials Research Express |
| spelling | doaj.art-fdf38d8e17774b50b45e7daf0829c2312023-08-09T16:18:45ZengIOP PublishingMaterials Research Express2053-15912022-01-0191111651810.1088/2053-1591/aca007Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatmentKai Li0https://orcid.org/0000-0001-8250-1770Hong Yang1Mengting Zou2Bingyuan Yang3Huibin Xu4https://orcid.org/0000-0002-1068-8473Huaxia Zhao5Henggang Yin6Yanlong Ma7AVIC Manufacturing Technology Institute, Beijing 100024, People’s Republic of ChinaCollege of Materials Science and Engineering, Chongqing University of Technology , Chongqing 400054, People’s Republic of ChinaCollege of Materials Science and Engineering, Chongqing University of Technology , Chongqing 400054, People’s Republic of ChinaCollege of Materials Science and Engineering, Chongqing University of Technology , Chongqing 400054, People’s Republic of ChinaCollege of Materials Science and Engineering, Chongqing University of Technology , Chongqing 400054, People’s Republic of ChinaAVIC Manufacturing Technology Institute, Beijing 100024, People’s Republic of ChinaJiangsu Jingchuan Materials Testing and Research Co., Ltd, Suzhou 215124, People’s Republic of ChinaCollege of Materials Science and Engineering, Chongqing University of Technology , Chongqing 400054, People’s Republic of ChinaThe microstructure and corrosion processes of a friction stir welded (FSW) 7075-T6 aluminum alloy joint, before and after anodizing surface treatment, have been characterized by advanced techniques, and the feasibility of anodizing treatment as a corrosion mitigation method has been evaluated. The results showed that different zones of the FSW joint had distinctly different microstructure and consequently different corrosion behavior in NaCl solution. Stable localized corrosion occurred in the transitional regions between the thermo-mechanically affected zone (TMAZ) and heat affected zone (HAZ), and was characterized by intergranular corrosion. The intergranular corrosion was ascribed to the galvanic coupling effect between Cu-rich grain boundary precipitates and the precipitates free zones (PFZs). Although anodizing and the subsequent sealing treatments could greatly improve the corrosion resistance of the base metal, the TMAZ/HAZ transition regions still showed much higher corrosion susceptibility than other regions. The high corrosion susceptibility of the FSW joint after anodizing treatment is not ascribed to the difference of the anodic oxide film in the regions, but the heterogeneous microstructure of the alloy beneath the anodic film. The present paper has shown that the stable localized corrosion in the FSW joint is intrinsically stemmed from the welding process itself and traditional mitigation method such as anodizing treatment cannot solve the problem; more effective corrosion mitigation methods are still awaited.https://doi.org/10.1088/2053-1591/aca0077075 aluminum alloyfriction stir welding (FSW)microstructureanodizingstable localized corrosion |
| spellingShingle | Kai Li Hong Yang Mengting Zou Bingyuan Yang Huibin Xu Huaxia Zhao Henggang Yin Yanlong Ma Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatment Materials Research Express 7075 aluminum alloy friction stir welding (FSW) microstructure anodizing stable localized corrosion |
| title | Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatment |
| title_full | Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatment |
| title_fullStr | Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatment |
| title_full_unstemmed | Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatment |
| title_short | Characterization and evaluation of stable localized corrosion in a 7075-T6 aluminum alloy FSW joint before and after anodizing treatment |
| title_sort | characterization and evaluation of stable localized corrosion in a 7075 t6 aluminum alloy fsw joint before and after anodizing treatment |
| topic | 7075 aluminum alloy friction stir welding (FSW) microstructure anodizing stable localized corrosion |
| url | https://doi.org/10.1088/2053-1591/aca007 |
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