Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content
Hypereutectic Al-Co alloys of various Co contents (7–20 weight % (wt.%) Co) were prepared by vacuum arc melting, aiming at investigating the influence of the cobalt content on the microstructure and corrosion behavior. Quite uniform and directional microstructures were attained. The obtained microst...
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| Format: | Article |
| Language: | English |
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MDPI AG
2016-02-01
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| Series: | Metals |
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| Online Access: | http://www.mdpi.com/2075-4701/6/3/46 |
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| author | Angeliki Lekatou Athanasios K. Sfikas Christina Petsa Alexandros E. Karantzalis |
| author_facet | Angeliki Lekatou Athanasios K. Sfikas Christina Petsa Alexandros E. Karantzalis |
| author_sort | Angeliki Lekatou |
| collection | DOAJ |
| description | Hypereutectic Al-Co alloys of various Co contents (7–20 weight % (wt.%) Co) were prepared by vacuum arc melting, aiming at investigating the influence of the cobalt content on the microstructure and corrosion behavior. Quite uniform and directional microstructures were attained. The obtained microstructures depended on the Co content, ranging from fully eutectic growth (7 wt.% and 10 wt.% Co) to coarse primary Al9Co2 predominance (20 wt.% Co). Co dissolution in Al far exceeded the negligible equilibrium solubility of Co in Al; however, it was hardly uniform. By increasing the cobalt content, the fraction and coarseness of Al9Co2, the content of Co dissolved in the Al matrix, and the hardness and porosity of the alloy increased. All alloys exhibited similar corrosion behavior in 3.5 wt.% NaCl with high resistance to localized corrosion. Al-7 wt.% Co showed slightly superior corrosion resistance than the other compositions in terms of relatively low corrosion rate, relatively low passivation current density and scarcity of stress corrosion cracking indications. All Al-Co compositions demonstrated substantially higher resistance to localized corrosion than commercially pure Al produced by casting, cold rolling and arc melting. A corrosion mechanism was formulated. Surface films were identified. |
| first_indexed | 2024-12-12T19:42:44Z |
| format | Article |
| id | doaj.art-8370c176e70a401f9d8298b1adcd596c |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-12T19:42:44Z |
| publishDate | 2016-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-8370c176e70a401f9d8298b1adcd596c2022-12-22T00:14:10ZengMDPI AGMetals2075-47012016-02-01634610.3390/met6030046met6030046Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co ContentAngeliki Lekatou0Athanasios K. Sfikas1Christina Petsa2Alexandros E. Karantzalis3Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110, GreeceDepartment of Materials Science and Engineering, University of Ioannina, Ioannina 45110, GreeceDepartment of Materials Science and Engineering, University of Ioannina, Ioannina 45110, GreeceDepartment of Materials Science and Engineering, University of Ioannina, Ioannina 45110, GreeceHypereutectic Al-Co alloys of various Co contents (7–20 weight % (wt.%) Co) were prepared by vacuum arc melting, aiming at investigating the influence of the cobalt content on the microstructure and corrosion behavior. Quite uniform and directional microstructures were attained. The obtained microstructures depended on the Co content, ranging from fully eutectic growth (7 wt.% and 10 wt.% Co) to coarse primary Al9Co2 predominance (20 wt.% Co). Co dissolution in Al far exceeded the negligible equilibrium solubility of Co in Al; however, it was hardly uniform. By increasing the cobalt content, the fraction and coarseness of Al9Co2, the content of Co dissolved in the Al matrix, and the hardness and porosity of the alloy increased. All alloys exhibited similar corrosion behavior in 3.5 wt.% NaCl with high resistance to localized corrosion. Al-7 wt.% Co showed slightly superior corrosion resistance than the other compositions in terms of relatively low corrosion rate, relatively low passivation current density and scarcity of stress corrosion cracking indications. All Al-Co compositions demonstrated substantially higher resistance to localized corrosion than commercially pure Al produced by casting, cold rolling and arc melting. A corrosion mechanism was formulated. Surface films were identified.http://www.mdpi.com/2075-4701/6/3/46Al-Co alloyshypereutecticAl9Co2complex metallic alloysvacuum arc meltingdirectional growthaqueous corrosionreverse polarizationpseudo-passivationRaman spectroscopy |
| spellingShingle | Angeliki Lekatou Athanasios K. Sfikas Christina Petsa Alexandros E. Karantzalis Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content Metals Al-Co alloys hypereutectic Al9Co2 complex metallic alloys vacuum arc melting directional growth aqueous corrosion reverse polarization pseudo-passivation Raman spectroscopy |
| title | Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content |
| title_full | Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content |
| title_fullStr | Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content |
| title_full_unstemmed | Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content |
| title_short | Al-Co Alloys Prepared by Vacuum Arc Melting: Correlating Microstructure Evolution and Aqueous Corrosion Behavior with Co Content |
| title_sort | al co alloys prepared by vacuum arc melting correlating microstructure evolution and aqueous corrosion behavior with co content |
| topic | Al-Co alloys hypereutectic Al9Co2 complex metallic alloys vacuum arc melting directional growth aqueous corrosion reverse polarization pseudo-passivation Raman spectroscopy |
| url | http://www.mdpi.com/2075-4701/6/3/46 |
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