预拉伸处理对2 A97薄板组织和性能的影响

通过室温拉伸、腐蚀试验、TEM等手段,研究人工时效前预拉伸处理对2A97铝锂合金组织和性能的影响。结果表明：在相同时效工艺下,经3%的预拉伸变形后,2A97合金的强度和耐蚀性能都有较大提高,其中抗拉强度提高了32 MPa,晶间腐蚀等级变为点蚀等级；预拉伸处理促进了时效过程中T1相在晶内的均匀弥散析出,降低了δ′相的含量,抑制了晶界平衡相的析出,从而改善了合金的强度和耐蚀性能。

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

The effect of pre-sretching processing before artificial aging on the microstructures and properties of 2A97 Al-Li alloy was in-vestigated 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 T1 phase 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 corro-sion property.