Effect of Hypoeutectic Sc Additions to Al-4.5 wt% Cu Under Different Cooling Rates
Lightweight materials are the best response to improving performance and efficiency of sport and transportation industrial products. Aluminum is one of the most attractive lightweight materials due to its low density and a high strength to weight ratio achievable through cold working and/or heat treatment. Age hardenable Al–Cu alloys are one of the strongest aluminium alloys available. Sc, though very expensive, is renowned for yielding the highest strength increase per atomic percent of any alloying addition in Al through grain refinement of hyper-eutectic Sc compositions and precipitation hardening. This paper studies the solidification of Al-4.5 wt% Cu with minor Sc additions (hypo-eutectic compositions) over a wide range of cooling rates. The objective is to determine the minimum Sc addition for a maximum strengthening effect while reducing typical processing steps. Based on the microstructures and mechanical properties analyses, a cost and time effective processing route is proposed for the 2000 series aluminum alloys.
KeywordsSolidification Aluminum–copper–scandium Cooling rate
The authors are grateful to the Natural Sciences and Engineering Research Council of Canada (NSERC), Novelis, the Canadian Space Agency (CSA), and the European Space Agency (ESA) for their financial support. Also the staff at the Institute of Materials Physics in Space (DLR) is acknowledged for their cooperation and help during EML experiments.
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