Effects of small additions of scandium and magnesium on the structure and properties of Al-Li-Cu-Zr alloy upon natural aging

The effects of alloying with scandium and magnesium on the structure and physico-mechanical properties of the Al-Li-Cu-Zr alloy in the process of its natural aging was studied using electron-microscopy, X-ray diffraction, and measurements of electrical resistance and mechanical properties. It was found that the alloying stimulates grain refinement, affects the kinetics of precipitation and the morphology of the metastable phases δ', θ″, θ', and enhances the strength properties. Structural constituents responsible for this enhancement under different alloying conditions were revealed