Containing Sc-al-cu-li-mg-zr Alloy Microstructure And Properties Of,

Four kinds of Al-Cu-Li-Mg-Zr alloys containing different percents of Sc were prepared using ingot metallurgy processing. The effects of small(or trace) additions of Sc on the microstructures and the room-temperature mechanical properties of Al-Cu-Li-Mg-Zr alloys and deformation-aging on the microstructures and the room-temperature mechanical properties of Al-Cu-Li-Mg-Zr-Sc alloy were studied by tensile test and TEM observations. The conclusions can be summarized as the followings:1 . The addition of 0. 10%Sc and 0.15%Sc can considerably improve the tensile mechanical properties of Al-3.5Cu-l.5Li-0.5Mg-0.12Zr alloys. However, the addition of 0.25%Sc reduce the strength of the alloy. Therefore, the favorable addition is 0.10-0.15% of Sc in these alloys.2. The addition of 0.10%Sc can eliminate the dendrite of AJ-3.5Cu-l.5Li-0.5Mg-0.12Zr alloy, but can not cause obvious grain refinement. The addition of 0.15%Sc and 0.25%Sc can cause strong grain refinement.3. The addition of 0.10%Sc can acceletate secondary Al3Sc or Al3(Sc1-xZrx) precipitated from a(Al) which is dispersed and coherent with the matrix and can strongly pin grain boundary and dislocation, stabilize substructures of these alloys, so it can strongly restrain recrystallization in the process of solution of the alloy. But addition of 0.15%Sc and 0.25%Sc drop the effects on restraining recrystallization of these alloys.4. Prior deformation leads to an acceleration of aging response and enhances strength greatly because of an increased density of refined Tl precipitations.5. The strength of the alloy improve with the increasing of pre-deformation. But too much pre-deformation lead to reducing of strength of the alloy. Therefore the favorable pre-deformation is about 3.5% under the experiment condition.6. The increasing prior deformation can increase the density and the number of refined 71 precipitations and make 71 phase distribute more dispersively and homogenously. But too much pre-deformation cause coarsed of Tl phase and distribute inhomogenously.