Effects of retrogression and re-aging process on microstructure and properties of 7055 aluminum alloy sheet

doi:10.13251/j.issn.0254-6051.2023.04.021

Abstract

Abstract: Microstructure and mechanical properties of 7055-aluminum alloy sheet after retrogression and re-aging were systematically studied by means of TEM, SEM, DSC, tensile test and conductivity testing. The results show that with the extension of retrogression time, strength of the alloy increases firstly and then decreases, meanwhile, the conductivity monotonically increases through the whole process. Compared with T6 state, after retrogression and re-aging, the precipitated phase space on grain boundary increases and intermittently distributes, and the size of strengthening phase in the crystal is grown to a certain extent. When the retrogression and re-aging process is 121 ℃×24 h+170 ℃×30 min+121 ℃×24 h, the 7055 aluminum alloy exhibits excellent comprehensive properties, of which the tensile strength is 630.75 MPa, the yield strength is 588.75 MPa, the conductivity is 34.75%IACS, and the fracture mechanism is mixed fracture.

Key words: 7055 aluminum alloy, retrogression and re-aging, mechanical properties, conductivity

CLC Number:

TG146.2⁺1

Cheng Zhiyuan, Sun Ning, Guo Fengjia, Wang Zhixiong, Li Tao, Wang Jingtao. Effects of retrogression and re-aging process on microstructure and properties of 7055 aluminum alloy sheet[J]. Heat Treatment of Metals, 2023, 48(4): 130-136.

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