Effect of Pre-sretching Processing on Microstructures and Properties of 2A97 Al-Li Alloy

The effect of pre-sretching processing before artificial aging on the microstructures and properties of 2A97 Al-Li alloy was investigated by using tensile test,corrosion test and transmission electron microscope(TEM) observations. The results show that under the same aging process, the tensile strength and the corrosion property of 2A97 Al-Li alloy are greatly increased after 3% pre-sretching; the tensile strength increases 32 MPa, and intergranular corrosion level changes to pitting corrosion. The pre-sretching promotes the T₁phase precipitation and makes its distribution more dispersive and homogeneous at matrix, reducing the content of the δ' phase, while the precipitation of equilibrium phase is restrained during the aging process, consequently improving the tensile strength and the corrosion property