The precipitation processes in quenched Al-Li (2090) alloy from the solid solution state , then heat treated at Ta =
460 K and 600 K have been investigated by Vickers Hardness (HV) measurements and Differential Scanning Calorimetry
(DSC). The overall activation energies associated with the transformation processes are evaluated using the DSC
thermograms and accordingly the kinetics of these processes has been characterized. Both Electron Microscopy (scanning
SEM and transmission TEM) and X-Ray Diffraction (XRD) are performed to clarify and confirm the obtained results. The
-Phase (Al3Li) and the T2-phase (Al6CuLi3) are exist in the alloy in addition to TB (Al7Cu4Li) phase in the Al - matrix.
Such existence is actively contributing to the strengthening of the alloy. Analysis of the results indicates coarsening of the
-phase is, preferable, at the grain boundaries. The lattice parameters and the particle size (D) of the existing phases could
be calculated using the Full-Prof computer program. The D of the -phase was found in the nano-scaled range. In addition,
the presence of Li in the alloy reduced the material density. The reduction in density by all means is a reduction in the fuel
consumption if the material is used in aircraft and automobile industries. In its turn, a fuel consumption reduction
minimizes environmental pollution.