The effect of strontium on the Mg{sub 2}Si precipitation process in 6201 aluminum alloy
- American Racing Equipment Inc., Rancho Dominguez, CA (United States). Aluminum Div.
- McGill Univ., Montreal, Quebec (Canada). Dept. of Mining and Metallurgical Engineering
A transmission electron microscopy (TEM) study of a 6201 aluminum alloy to which controlled strontium additions were made has revealed important differences compared to the same alloy free of strontium. In the as-cast state, strontium favors the formation of {alpha}-AlFeSi (Al{sub 8}Fe{sub 2}Si) rather than {beta}-AlFeSi (Al{sub 5}FeSi) phase, resulting in a greater quantity of excess silicon present in the strontium-treated alloy. During heat treatment, the excess silicon allows a greater density of finer B{double_prime}-Mg{sub 2}Si precipitates to form, leading to increased tensile strength values and increased electrical resistivity. Strontium also retards the growth of the precipitates formed during heat treatment and inhibits formation on the equilibrium {beta}-Mg{sub 2}Si phase. As a result, the strontium-treated alloy exhibits a resistance to overaging.
- Sponsoring Organization:
- Natural Sciences and Engineering Research Council of Canada, Ottawa, ON (Canada)
- OSTI ID:
- 514758
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 6 Vol. 28; ISSN 1073-5623; ISSN MMTAEB
- Country of Publication:
- United States
- Language:
- English
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