Aluminum alloys strengthened with coherent (L1<sub>2</sub>), nanosize Al<sub>3</sub>Sc precipitates may be used as structural materials at elevated temperatures. They are creep resistant at 300°C and exhibit a threshold stress, below which creep is not measurable. Introducing ternary alloying additions, such as rare-earth elements (RE=Y, Dy, Er), that segregate within Al<sub>3</sub>Sc...