Abstract:To investigate the influence of solution and aging parameters on the strengthening and toughening mechanisms of 2195 Al-Li alloy, orthogonal experiments combined with range analysis were conducted. The regulatory rules of heat treatment regimes on the mechanical properties and microstructure of the alloy were illustrated. The results indicate that during solution treatment process, the 2195 Al-Li alloy exhibits significantly higher sensitivity to solution temperature than to solution time. Thus, to design the solution process, the appropriate solution temperature should be given priority consideration, followed by optimization of the corresponding holding time based on this temperature. In the aging stage, the strengthening effect of the 2195 Al-Li alloy is primarily dominated by the T1 phase, and its precipitation behavior is strictly regulated by aging temperature and time. Under natural aging (under-aged state), the precipitated phases are predominantly δ′ phases, resulting in a relatively limited strengthening effect. At the peak aging stage, the T1 phases exhibit characteristics of fine size, dispersion, and high density, and at this time, the strength of the alloy achieves its maximum value. Upon entering the over-aged stage, the coarsening of T1 and δ′ phases lead to a decrease in alloy strength. Consequently, precise control of aging parameters provides an effective means of tailoring the type, size, and spatial distribution of strengthening precipitates, thereby optimizing the comprehensive mechanical properties of the 2195 Al-Li alloy to meet the requirements of its forming processes and structural applications.