Effect of pre-stretching amount on microstructure and properties of 2050 Al-Li alloy

doi:10.13251/j.issn.0254-6051.2022.06.011

Abstract

Abstract: Effect of pre-stretching processing after solution treatment on tensile properties, intergranular corrosion resistance and microstructure of the artificial aged 2050 Al-Li alloy were studied by means of tensile test, intergranular corrosion test and transmission electron microscope(TEM). The results show that the yield strength and ultimate tensile strength at L and LT directions of the 2050 Al-Li alloy increase gradually with the increase of pre-stretching amount, and tend to be stable when the pre-stretching amount is over 4.0%, elongation decreases rapidly at first and then finally keep stable. With the increase of pre-stretching amount, the corrosion morphology changes from intergranular corrosion to pitting, and the pitting depth decreases gradually. The pre-stretching processing promotes the T₁ phase precipitation in the grains and makes its distribution more dispersive and homogeneous, while the precipitation at grain boundary is restrained during the artificial aging, which consequently improves the tensile strength and the intergranular corrosion resistance. When the pre-stretching amount is 5.0%, the optimum tensile strength and intergranular corrosion resistance is obtained for the alloy.

Key words: 2050 Al-Li alloy, pre-stretching, tensile properties, intergranular corrosion resistance, T₁ phase

CLC Number:

TG146.2

Yu Juan, Feng Zhaohui, Zhao Weiyi, Yao Yong, You Wen. Effect of pre-stretching amount on microstructure and properties of 2050 Al-Li alloy[J]. Heat Treatment of Metals, 2022, 47(6): 64-68.

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