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The effects of chemical composition, solidification rate, and homogenization on the intermetallic particle microstructure of AA8XXX aluminum alloys for battery foil applications
The growing demand for high-performance lithium-ion batteries, driven by the electric vehi-cle (EV) market, necessitates the development of current collectors that offer both superior electrical conductivity and enhanced mechanical properties. AA1XXX series aluminum al- loys, commonly used in batter...
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| Format: | Thesis |
| Language: | English |
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Department of Mechanical Engineering
2025
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| _version_ | 1867613298846859264 |
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| access_status_str | Open Access |
| author | Maluleka, Tshepo |
| author2 | George, Sarah |
| author_browse | George, Sarah Maluleka, Tshepo |
| author_facet | George, Sarah Maluleka, Tshepo |
| author_sort | Maluleka, Tshepo |
| collection | Thesis |
| description | The growing demand for high-performance lithium-ion batteries, driven by the electric vehi-cle (EV) market, necessitates the development of current collectors that offer both superior electrical conductivity and enhanced mechanical properties. AA1XXX series aluminum al- loys, commonly used in battery applications, are limited by their strength and ductility. As an alternative, AA8XXX aluminum alloys, particularly those based on the Al-Fe-Si system, show promise due to their improved strength. However, their intermetallic particle (IMP) microstructure needs to be understood for optimal performance. This research investigates the impact of chemical composition, cooling rate, and homoge- nization processes on the IMP microstructure of AA8021 and AA8079 alloys, which are poten-tial candidate alloys for this application. Using 2D and 3D analytical approaches supported by analytical tools including light microscopy (LM), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and X-ray diffraction (XRD). The study identified three primary morphologies: plate-shaped, feathery/skeletal, and needle-shaped, corresponding to Al3Fe, AlmFe, and Al6Fe phases. The results reveal that higher Fe content in AA8021 leads to a higher volume fraction of finer IMPs, while higher Si content in AA8079 enhances the stability of Al3Fe and reduces the presence of AlmFe. Further- more, cooling rate significantly influences IMP morphology and phase stability, with higher cooling rates favoring the formation of finer, metastable phases at the surface. Homogeniza-tion treatments induce phase transformations from metastable Al6Fe and AlmFe to the stable Al3Fe phase, improving the uniformity and distribution of IMPs. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/42412 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:33:55.830Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Department of Mechanical Engineering |
| publisherStr | Department of Mechanical Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/42412 The effects of chemical composition, solidification rate, and homogenization on the intermetallic particle microstructure of AA8XXX aluminum alloys for battery foil applications Maluleka, Tshepo George, Sarah AA8XXX battery The growing demand for high-performance lithium-ion batteries, driven by the electric vehi-cle (EV) market, necessitates the development of current collectors that offer both superior electrical conductivity and enhanced mechanical properties. AA1XXX series aluminum al- loys, commonly used in battery applications, are limited by their strength and ductility. As an alternative, AA8XXX aluminum alloys, particularly those based on the Al-Fe-Si system, show promise due to their improved strength. However, their intermetallic particle (IMP) microstructure needs to be understood for optimal performance. This research investigates the impact of chemical composition, cooling rate, and homoge- nization processes on the IMP microstructure of AA8021 and AA8079 alloys, which are poten-tial candidate alloys for this application. Using 2D and 3D analytical approaches supported by analytical tools including light microscopy (LM), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and X-ray diffraction (XRD). The study identified three primary morphologies: plate-shaped, feathery/skeletal, and needle-shaped, corresponding to Al3Fe, AlmFe, and Al6Fe phases. The results reveal that higher Fe content in AA8021 leads to a higher volume fraction of finer IMPs, while higher Si content in AA8079 enhances the stability of Al3Fe and reduces the presence of AlmFe. Further- more, cooling rate significantly influences IMP morphology and phase stability, with higher cooling rates favoring the formation of finer, metastable phases at the surface. Homogeniza-tion treatments induce phase transformations from metastable Al6Fe and AlmFe to the stable Al3Fe phase, improving the uniformity and distribution of IMPs. 2025-12-05T09:05:57Z 2025-12-05T09:05:57Z 2025 2025-12-05T08:42:42Z Thesis / Dissertation Masters MSc http://hdl.handle.net/11427/42412 eng application/pdf Department of Mechanical Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | AA8XXX battery Maluleka, Tshepo The effects of chemical composition, solidification rate, and homogenization on the intermetallic particle microstructure of AA8XXX aluminum alloys for battery foil applications |
| thesis_degree_str | Master's |
| title | The effects of chemical composition, solidification rate, and homogenization on the intermetallic particle microstructure of AA8XXX aluminum alloys for battery foil applications |
| title_full | The effects of chemical composition, solidification rate, and homogenization on the intermetallic particle microstructure of AA8XXX aluminum alloys for battery foil applications |
| title_fullStr | The effects of chemical composition, solidification rate, and homogenization on the intermetallic particle microstructure of AA8XXX aluminum alloys for battery foil applications |
| title_full_unstemmed | The effects of chemical composition, solidification rate, and homogenization on the intermetallic particle microstructure of AA8XXX aluminum alloys for battery foil applications |
| title_short | The effects of chemical composition, solidification rate, and homogenization on the intermetallic particle microstructure of AA8XXX aluminum alloys for battery foil applications |
| title_sort | effects of chemical composition solidification rate and homogenization on the intermetallic particle microstructure of aa8xxx aluminum alloys for battery foil applications |
| topic | AA8XXX battery |
| url | http://hdl.handle.net/11427/42412 |
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