Effect of Aging Regime on Microstructure and Mechanical Properties of 2195 Al-Li Alloy

Abstract:

The microstructure and mechanical properties of 2195 Al-Li alloy under different aging regimes were analyed by hardness test, tensile test and transmission electron microscopy. The results show that the results show that the peak aging system of single stage aging is 160℃ × 56h and 190℃ × 16h. Its peak tensile strength is 565MPa and 541MPa, and its elongation is 6.3% and 7.1%, respectively. The tensile strength and elongation of the alloy aged at 190℃ × 4h + 160℃ × 32h are 588MPa and 13.5%. Both of them are much better than single - stage aging alloys. The elonged T₁ phase and compact region in the double stage aging alloy matrix play an important role in improving the strength. In addition, the narrow precipitation free zone along grain boundary and the cell structure inside grains are the main factors for the performance enhancement of plasticity. The double stage aging system of 190℃ × 4h + 160℃ × 32h can obtain better comprehensive mechanical properties than that of single stage aging.