Fabrication of a model specimen for understanding micro-galvanic corrosion at the boundary of α-Mg and β-Mg17Al12
A model specimen with a single boundary of the α/β phase simulating Mg-Al alloys was successfully fabricated by spark plasma sintering. A small electrode area of α phase or β phase was prepared using the model specimen, and the OCPs (open-circuit potentials) of each phase and a small electrode area...
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| Format: | Article |
| Language: | English |
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KeAi Communications Co., Ltd.
2023-01-01
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| Series: | Journal of Magnesium and Alloys |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2213956722002742 |
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| author | Zheng Shao Masashi Nishimoto Izumi Muto Yu Sugawara |
| author_facet | Zheng Shao Masashi Nishimoto Izumi Muto Yu Sugawara |
| author_sort | Zheng Shao |
| collection | DOAJ |
| description | A model specimen with a single boundary of the α/β phase simulating Mg-Al alloys was successfully fabricated by spark plasma sintering. A small electrode area of α phase or β phase was prepared using the model specimen, and the OCPs (open-circuit potentials) of each phase and a small electrode area containing the α/β phase boundary in 0.1 M NaCl at pH 8.0 were compared: the β phase exhibited a higher potential, and the α phase showed a lower potential. The OCP of the small area containing the α/β phase boundary was the intermediate value of these phases. In a small area containing α/β phase boundary, discoloration and gas bubbles were observed on the α phase, but no bubble generation was detected on the β phase. The gas bubbles were initially generated on the α phase near the β phase, but as the discoloration (corrosion) of the α phase approached the β phase, the bubbles were generated on the β phase. In micro-galvanic corrosion of the α and β phases, the β phase did not always function as the preferred cathode. The α phase partially corroded (or discolored) and became the anodes, so that the surrounding areas were most likely to be the cathodes. When corroded areas (anodes) in the α phase approached the β phase, the β phase would become cathodes. In addition to the micro-galvanic corrosion mechanism, the role of Al in corrosion resistance at the α/β phase boundary was determined by surface analysis. |
| first_indexed | 2024-04-10T08:50:09Z |
| format | Article |
| id | doaj.art-634615a41c314d47a1296f9dcfc6e1ea |
| institution | Directory Open Access Journal |
| issn | 2213-9567 |
| language | English |
| last_indexed | 2024-04-10T08:50:09Z |
| publishDate | 2023-01-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Journal of Magnesium and Alloys |
| spelling | doaj.art-634615a41c314d47a1296f9dcfc6e1ea2023-02-22T04:30:23ZengKeAi Communications Co., Ltd.Journal of Magnesium and Alloys2213-95672023-01-01111137153Fabrication of a model specimen for understanding micro-galvanic corrosion at the boundary of α-Mg and β-Mg17Al12Zheng Shao0Masashi Nishimoto1Izumi Muto2Yu Sugawara3Corresponding authors.; Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-0579, JapanDepartment of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-0579, JapanCorresponding authors.; Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-0579, JapanDepartment of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-0579, JapanA model specimen with a single boundary of the α/β phase simulating Mg-Al alloys was successfully fabricated by spark plasma sintering. A small electrode area of α phase or β phase was prepared using the model specimen, and the OCPs (open-circuit potentials) of each phase and a small electrode area containing the α/β phase boundary in 0.1 M NaCl at pH 8.0 were compared: the β phase exhibited a higher potential, and the α phase showed a lower potential. The OCP of the small area containing the α/β phase boundary was the intermediate value of these phases. In a small area containing α/β phase boundary, discoloration and gas bubbles were observed on the α phase, but no bubble generation was detected on the β phase. The gas bubbles were initially generated on the α phase near the β phase, but as the discoloration (corrosion) of the α phase approached the β phase, the bubbles were generated on the β phase. In micro-galvanic corrosion of the α and β phases, the β phase did not always function as the preferred cathode. The α phase partially corroded (or discolored) and became the anodes, so that the surrounding areas were most likely to be the cathodes. When corroded areas (anodes) in the α phase approached the β phase, the β phase would become cathodes. In addition to the micro-galvanic corrosion mechanism, the role of Al in corrosion resistance at the α/β phase boundary was determined by surface analysis.http://www.sciencedirect.com/science/article/pii/S2213956722002742Magnesium alloyα/β phase boundaryMicro-scale observation techniqueMicro-galvanic corrosionSpark plasma sintering |
| spellingShingle | Zheng Shao Masashi Nishimoto Izumi Muto Yu Sugawara Fabrication of a model specimen for understanding micro-galvanic corrosion at the boundary of α-Mg and β-Mg17Al12 Journal of Magnesium and Alloys Magnesium alloy α/β phase boundary Micro-scale observation technique Micro-galvanic corrosion Spark plasma sintering |
| title | Fabrication of a model specimen for understanding micro-galvanic corrosion at the boundary of α-Mg and β-Mg17Al12 |
| title_full | Fabrication of a model specimen for understanding micro-galvanic corrosion at the boundary of α-Mg and β-Mg17Al12 |
| title_fullStr | Fabrication of a model specimen for understanding micro-galvanic corrosion at the boundary of α-Mg and β-Mg17Al12 |
| title_full_unstemmed | Fabrication of a model specimen for understanding micro-galvanic corrosion at the boundary of α-Mg and β-Mg17Al12 |
| title_short | Fabrication of a model specimen for understanding micro-galvanic corrosion at the boundary of α-Mg and β-Mg17Al12 |
| title_sort | fabrication of a model specimen for understanding micro galvanic corrosion at the boundary of α mg and β mg17al12 |
| topic | Magnesium alloy α/β phase boundary Micro-scale observation technique Micro-galvanic corrosion Spark plasma sintering |
| url | http://www.sciencedirect.com/science/article/pii/S2213956722002742 |
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