| The anisotropy of mechanical properties of Al-Li alloy and the improvement of its properties by electric field are investigated. Contributions of each precipitate to yielding strength in various directions are studied by reversion treatment and the exponential addition rule. Contribution of T1 phase in lognitudinal direction is the smallest, and the transverse one is the biggest. While / phase enhances the anisotropy in the early stage of aging treatment. Ce increases the rolling texture, thereby increases the anisotropy. And Ce minishes the contribution of T1 phase to strength mainly in the transverse direction, reduces difference of the contribution of / phase to strength in various directions, thereby lessens the anisotropy. Besides, it embarrasses the aging course to a certain extent. Effects of electric field upon Al-Li alloy are studied by analyzing characters of fractured surfaces and microcosmic distribution of alloying elements. The electric field improves the capability of plastic deformation of Al-Li alloy, loweres short- transverse delamination. It also speeds segregation of alloying elements at grain boundary. The electric field improves the plasticity of Al-Li alloy markedly, but it doesn't change the strength visibly. The author discuss mechanisms by which electric field affects dissolution, precipitation and segregation of alloying elements. |
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