Effect of Cu content on microstructure, mechanical properties and corrosion behavior of Al-Li alloy

doi:10.13251/j.issn.0254-6051.2023.10.032

Abstract

Abstract: Microstructure, mechanical properties and corrosion properties of Al-xCu-1.0Li-0.5Mg-0.4Zn-0.4Mn(x=2.0, 3.2, 3.4, 3.6, 4.0) alloy plates treated by T6 aging were investigated by means of scanning electron microscope (SEM),transmission electron microscope (TEM), mechanical testing machine and electrochemical workstation. The results show that the strength of the alloy increases with the increase of Cu content. When the Cu content is 3.4%, the alloy has optimal properties with tensile strength of 360.4 MPa and elongation of 17.1%. The fracture modes of aluminum-copper-lithium alloy exhibit ductile fracture at Cu content of 2.0% and 3.4%, mixed fracture at Cu content of 3.2%, and brittle fracture at Cu content of 3.6% and 4.0%. The alloy exhibits optimal corrosion resistance when the Cu content is 3.2%. With the increase of Cu content, it is beneficial to precipitate of T₁ phase and cubic phase, which leads to improve the mechanical properties of the alloy, while excessive cubic phase may reduce the corrosion resistance.

Key words: Al-Li alloy, Cu content, microstructure, corrosion behavior

CLC Number:

TG146.2

Zong Kepu, Lu Yalin, Wang Jian, Li Xingcheng, Zhou Dongshuai. Effect of Cu content on microstructure, mechanical properties and corrosion behavior of Al-Li alloy[J]. Heat Treatment of Metals, 2023, 48(10): 207-214.

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