Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1448359 | Acta Materialia | 2008 | 9 Pages |
Abstract
Upon aging at 300–450 °C, nanosize, coherent Al3(Sc1−xTix) precipitates are formed in pure aluminum micro-alloyed with 0.06 at.% Sc and 0.06 at.% Ti. The outstanding coarsening resistance of these precipitates at these elevated temperatures (61–77% of the melting temperature of aluminum) is explained by the significantly smaller diffusivity of Ti in Al when compared to that of Sc in Al. Furthermore, this coarse-grained alloy exhibits good compressive creep resistance for a castable, heat-treatable aluminum alloy: the creep threshold stress varies from 17 MPa at 300 °C to 7 MPa at 425 °C, as expected if the climb bypass by dislocations of the mismatching precipitates is hindered by their elastic stress fields.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Marsha E. van Dalen, David N. Seidman, David C. Dunand,