Effect of low heating rate aging treatment on properties of Al-Zn-Mg-Er-Zr alloy

doi:10.13251/j.issn.0254-6051.2023.03.002

Abstract

Abstract: Effect of two different aging processes at 120 ℃ on mechanical properties and electrical conductivity of Al-5Zn-3Mg-0.1Er-0.1Zr alloy was studied by scanning electron microscope (SEM), microhardness tester and conductometer. The results show that compared with the aging process by directly putting specimens at 120 ℃, the conductivity of the tested alloy after 5 h slow heating to 120 ℃ aging process is increased to 30.77%IACS, and the hardness, tensile strength, yield strength and elongation are increased to 186.6 HV0.2, 538 MPa, 454 MPa and 17.5%, respectively. Both the fracture modes are ductile-brittle mixed fracture for the alloy treated by the two different aging processes, but for the alloy treated by 5 h slow heating to 120 ℃ aging, the dimple density is higher, and the shear plane characteristic is reduced.

Key words: Al-Zn-Mg alloy, aging treatment, electrical conductivity, mechanical properties

CLC Number:

TG146.21

Qiu Chen, Rong Li, Wei Wu, Wang Wei, Wen Shengping, Huang Hui, Dong Yang, Wang Yugang. Effect of low heating rate aging treatment on properties of Al-Zn-Mg-Er-Zr alloy[J]. Heat Treatment of Metals, 2023, 48(3): 8-11.

References

[1]Azarniya A, Taheri A K, Taheri K K. Recent advances in ageing of 7××× series aluminum alloys: A physical metallurgy perspective[J]. Journal of Alloys and Compounds, 2019, 781: 945-983.
[2]Chen S Y, Li J Y, Hu G Y, et al. Effect of Zn/Mg ratios on SCC, electrochemical corrosion properties and microstructure of Al-Zn-Mg alloy[J]. Journal of Alloys and Compounds, 2018, 757: 259-264.
[3]Wu H, Wen S P, Huang H, et al. Hot deformation behavior and constitutive equation of a new type Al-Zn-Mg-Er-Zr alloy during isothermal compression[J]. Materials Science & Engineering A, 2016, 651: 415-424.
[4]Wu H, Wen S P, Huang H, et al. Hot deformation behavior and processing map of a new type Al-Zn-Mg-Er-Zr alloy[J]. Journal of Alloys and Compounds, 2016, 685: 869-880.
[5]孙文会, 张永安, 李锡武, 等. 固溶热处理对7136铝合金组织性能的影响[J]. 航空材料学报, 2014, 34(3): 35-41.
Sun Wenhui, Zhang Yongan, Li Xiwu, et al. Effect of solution treatment on microstructures and mechanical properties of 7136 aluminum alloy[J]. Journal of Aeronautical Materials, 2014, 34(3): 35-41.
[6]Xiao W, Wang J W, Sun L, et al. Theoretical investigation of the strengthening mechanism and precipitation evolution in high strength Al-Zn-Mg alloys[J]. Physical Chemistry Chemical Physics, 2018, 19: 13616.
[7]Liu M, Klobes B, Maier K. On the age-hardening of an Al-Zn-Mg-Cu alloy: A vacancy perspective[J]. Scripta Materialia, 2011, 64(1): 21-24.
[8]Liu Y, Jiang D, Xie W, et al. Solidification phases and their evolution during homogenization of a DC cast Al-8.35Zn-2.5Mg-2.25Cu alloy[J]. Materials Characterization, 2014, 93: 173-183.
[9]Liu J J, Li H Y, Li D W, et al. Application of novel physical picture based on artificial neural networks to predict microstructure evolution of Al-Zn-Mg-Cu alloy during solid solution process[J]. Transactions of Nonferrous Metals Society of China, 2015, 25(3): 944-953.
[10]万彩云, 陈江华, 杨修波, 等. 7×××系AlZnMgCu铝合金早中期时效[J]. 电子显微学报, 2010, 29(5): 455-460.
Wan Caiyun, Chen Jianghua, Yang Xiubo, et al. Study of the early & mid-stage hardening precipitates in a 7××× AlZnMgCu aluminium alloy[J]. Journal of Chinese Electron Microscopy Society, 2010, 29(5): 455-460.
[11]Ren J, Wang R C, Feng Y, et al. Microstructure evolution and mechanical properties of an ultrahigh strength Al-Zn-Mg-Cu-Zr-Sc (7055) alloy processed by modified powder hot extrusion with post aging[J]. Vacuum, 2019, 161: 6497-6511.
[12]Wang Z X, Jiang H H, Li H, et al. Effect of solution-treating temperature on the intergranular corrosion of a peak-aged Al-Zn-Mg-Cu alloy[J]. Journal of Materials Research and Technology, 2020, 9(3): 6497-6511.
[13]Rana R S, Purohit R, Das S. Reviews on the influences of alloying elements on the microstructure and mechanical properties of aluminum alloys and aluminum alloy composites[J]. International Journal of Scientific and Research Publications, 2012, 2: 1-7.
[14]刘馨忆, 王晨充, 赵彦林, 等. 多级时效处理对Al-4.74Zn-2.13Mg-1.20Cu合金性能的影响[J]. 材料热处理学报, 2019, 40(5): 58-64.
Liu Xinyi, Wang Chenchong, Zhao Yanlin, et al. Effect of multi-stage aging treatment on properties of Al-4.74Zn-2.13Mg-1.20Cu alloy[J]. Transactions of Materials and Heat Treatment, 2019, 40(5): 58-64.
[15]Ke B, Ye L Y, Zhang Y, et al. Enhanced strength and electrical conductivities of an Al-Zn-Mg aluminum alloy through a new aging process[J]. Materials Letters, 2021, 304: 130586.
[16]Wen H, Topping T D, Isheim D, et al. Strengthening mechanisms in a high-strength bulk nanostructured Cu-Zn-Al alloy processed via cryomilling and spark plasma sintering[J]. Acta Materialia, 2013, 61(8): 2769-2782.
[17]Ardell A J. Precipitation hardening[J]. Metallurgical Transactions A, 1985, 16: 2131-2165.
[18]Seidman D N, Marquis E A, Dunand D C. Precipitation strengthening at ambient and elevated temperatures of heat-treatable Al(Sc) alloys[J]. Acta Materialia, 2002, 50(16): 4021-4035.
[19]Ma P, Liu C, Chen Q, et al. Natural-ageing-enhanced precipitation near grain boundaries in high-strength aluminum alloy[J]. Journal of Materials Science & Technology, 2020, 42(11): 107-113.