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Early microstructural evolution and deformation behavior in solution-heat-treated aluminum-lithium alloys

Thesis/Dissertation ·
OSTI ID:6929653

The binary aluminum-lithium system is age-hardened by the metastable phase [delta][prime] (Al[sub 3]Li). The [delta][prime] precipitates are present in volume fractions of [approximately] 0.2 in commercial Al-Li based alloys and thus affect many of the mechanical properties. In this investigation, the formation of [delta][prime] during rapid quenching after solution heat treatment is compared with the formation behavior during slower quenching in alloys with commercially important Cu and Mg additions. The alloys used were in wt.% Al-2.4% Li-0.11Zr, Al-2.45Li-3.15Cu-0.12Zr, and Al-2.6Li-1Cu-0.5Mg-0.5Zr. The formation of the microstructures in the different alloys during both rapid and slow quench rates, and the effects of the microstructural features on the tensile deformation behavior were studied. The microstructure produced by slow air cooling displayed higher tensile elongation and strength as compared with the microstructure produced by rapid water quenching.

Research Organization:
California Univ., Berkeley, CA (United States)
OSTI ID:
6929653
Country of Publication:
United States
Language:
English