Hight-temperature Aluminum Alloys

Aluminum alloys with Li additions (to increase strength and stiffness and to decrease density), and rare earth element (RE) additions (to improve creep resistance) have the potential to replace some heavier Ti-based components in energy generation applications.  Addition of Li results in the precipitation of a large volume fraction of the strengthening Al₃Li phase, as well as significantly increasing the elastic modulus and reducing density.  Dilute additions of Sc and rare earth elements (RE) to Al result in the precipitation of nanometric ordered Al₃(Sc,RE) precipitates, greatly improving the strength and creep resistance of Al alloys.

M.E. Krug, D.C. Dunand, D.N. Seidman, "Composition Profiles within Al₃Li and Al₃Sc/Al₃Li Nanoscale Precipitates in Aluminum", Applied Physics Letters, 92, 124107 (2008).

This research is supported by the United States Department of Energy through Grant No. DE-FG02-98ER45721.  The LEAP tomograph was purchased with funding from the NSF-MRI Grant No. DMR-0420532 and ONR-DURIP Grant No. N00014-0400798 programs.