Aging of an Al-Li-Cu-Zr alloy after quenching and deformation over a wide temperature interval

Electron microscopy and measurements of mechanical properties were used to study the influence of the deformation temperature on precipitation of a supersaturated solid solution and properties of the 1450 alloy of the Al-Li-Cu-Zr system during subsequent natural or artificial aging. It is shown that the deformation conditions influence the kinetics, morphology, volume fraction, and nucleation character of the precipitating delta'-theta'-, and T-1-phases. The relationship between the formation of composite delta'/theta'-particles and thermal stability of the Al-Cu-based phases (theta '' and theta') is discussed. A consideration is given to the reasons responsible for changes in the mechanical properties of the artificially aged alloy as a function of the deformation temperature.