Iron and silicon are the major impurities in the 1000 series of wrought aluminum alloys. As the aluminum is recycled, it picks up more and more of these impurities which cannot economically be refined out of the aluminum. When the concentration of these impurities reaches a certain limit (maximum limit in 1000 series is 1 weight percent (Fe+Si)), the aluminum must be downgraded. The Fe and Si form brittle intermetallic phases in these alloys. The two main phases are the plate-like $ beta$-AlFeSi (Al$ sb5$FeSi) and $ alpha$-AlFeSi (Al$ sb8$Fe$ sb2$Si) which has a Chinese Script morphology. The mechanical properties of these alloys are believed to depend largely on the nature of these intermetallics. / In the first part of this study, the conditions at which the intermetallics form, along with the ability of strontium to modify them were investigated. The second part consisted of determining how the morphology of the Al-Fe-Si phases affects the mechanical properties of the worked product. It was found that the formation of the Chinese Script morphology is promoted with increasing cooling rates, Fe/Si ratios and additions of strontium. However, the relative amount of Chinese Script was found to decrease with increasing (Fe+Si) levels. Tensile testing and formability testing (Erichsen ball punch deformation test) revealed that the presence of a Chinese Script morphology of Al-Fe-Si intermetallics (as opposed to the plate-like morphology) imparts no significant beneficial effect on the formability of the final rolled sheet.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.26424 |
| Date | January 1994 |
| Creators | Stephen, Gail |
| Contributors | Gruzleski, J. E. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Mining and Metallurgical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001430335, proquestno: MM99983, Theses scanned by UMI/ProQuest. |
Page generated in 0.0021 seconds