Optimization of heat treatment process of spray-formed 7055 high strength aluminum alloy and its application

doi:10.13251/j.issn.0254-6051.2022.01.039

Abstract

Abstract: Based on the spray-formed 7055 aluminum alloy after twice extrusion treatment, the microstructure and properties of the tested alloy under different aging processes were studied by means of SEM, optical microscope, hardness tester and tensile testing machine. The results show that compared with the single-stage aging process, after two-stage aging treatment at 120 ℃ for 6 h and at 160 ℃ for 2 h, the precipitates are uniformly distributed in the matrix with shape of short rod, which the average size along the length and width direction is 500 nm and 10 nm, respectively, and the aging peak hardness is 196.4 HV0.05. The tensile strength of the tested alloy treated by two-stage aging process at 298, 398, 498 and 598 K is 855, 792, 688 and 360 MPa, respectively, and the elongation after fracture is 14%, 11%, 9% and 8%, respectively. The spray-formed 7055 aluminum alloy treated by the two-stage aging treatment process is applied to the preparation of hub fastener products, and is subjected to sulfuric acid anodizing treatment, which can make the fastener specimens have high strength, high hardness and high corrosion resistance at the same time, and it is expected to be more widely used.

Key words: 7055 aluminum alloy, spray-formed, two-stage aging, microstructure, mechanical properties

CLC Number:

TG146.2

Wang Jiahui, Chen Wenhao, Zhang Yu, Jiang Zhuoao, Wang Qinghang, Zhao Lingyu. Optimization of heat treatment process of spray-formed 7055 high strength aluminum alloy and its application[J]. Heat Treatment of Metals, 2022, 47(1): 239-244.

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