Effect of solution treatment on microstructure and properties of rare earth modified Al-Zn-Mg-Cu alloy

doi:10.13251/j.issn.0254-6051.2023.03.006

Abstract

Abstract: Effects of solution treatment time at 475 ℃ on the microstructure and properties of Al-Zn-Mg-Cu alloys with different contents(7055, 7055-Pr, 7055-Er, 7055-Pr-Er alloys) were studied by OM, SEM, EDS and tensile test. The results show that the strengths of the four alloys all increase firstly and then decrease with the increase of solution treatment time. The addition of rare earth Pr and Er can reduce the residual phases in the matrix, refine the grains, thereby improving the elongation of the alloys. The rare earth Pr has a better effect on improving elongation of the tested alloy than the rare earth Er, while the Er has a greater effect on the strength improvement of the tested alloy. Appropriate solution treatment can optimize the number and size of residual phases and secondary phases in the matrix, thereby affecting the fracture morphologies and mechanical properties of the alloys. After solution treatment at 475 ℃ for 60 min, the tensile strength of the 7055-Er alloy reaches the maximum value of 665 MPa, while the elongation of the 7055-Pr alloy reaches the maximum value of 14.9%.

Key words: aluminum alloy, heat treatment, rare earth, microstructure, mechanical properties

CLC Number:

TG146.2

Deng Hongling, Zhang Siyu, Zhong Huilong, Li Shengci, Qi Liang, Chen Jiqiang. Effect of solution treatment on microstructure and properties of rare earth modified Al-Zn-Mg-Cu alloy[J]. Heat Treatment of Metals, 2023, 48(3): 32-38.

References

[1]Chung T, Yang Y, Shiojiri M, et al. An atomic scale structural investigation of nanometre-sized η′ precipitates in the 7050 aluminium alloy[J]. Acta Materialia, 2019, 174: 351-368.
[2]Khan M A, Wang Y, Anjum M J, et al. Effect of heat treatment on the precipitate behavior, corrosion resistance and high temperature tensile properties of 7055 aluminum alloy synthesis by novel spray deposited followed by hot extrusion[J]. Vacuum, 2020, 174: 109185.
[3]薛克敏, 李云辉, 许兵, 等. 时效制度对新型Al-Zn-Mg-Cu合金组织与性能的影响[J]. 金属热处理, 2021, 46(3): 1-7.
Xue Kemin, Li Yunhui, Xu Bing, et al. Effect of aging on microstructure and properties of new Al-Zn-Mg-Cu alloy[J]. Heat Treatment of Metals, 2021, 46(3): 1-7.
[4]Marlaud T, Deschamps A, Bley F, et al. Influence of alloy composition and heat treatment on precipitate composition in Al-Zn-Mg-Cu alloys[J]. Acta Materialia, 2010, 58(1): 248-260.
[5]王井井, 黄元春, 刘宇, 等. 时效工艺对Al-Zn-Mg-Cu-Zr-Er铝合金组织与耐腐蚀性影响[J]. 有色金属科学与工程, 2018, 9(2): 47-55.
Wang Jingjing, Huang Yuanchun, Liu Yu, et al. Influence of aging treatment on the microstructure and corrosion properties of Al-Zn-Mg-Cu-Zr-Er aluminum alloy[J]. Nonferrous Metals Science and Engineering, 2018, 9(2): 47-55.
[6]Zhong H, Li S, Wu J, et al. Effects of retrogression and re-aging treatment on precipitation behavior, mechanical and corrosion properties of a Zr+Er modified Al-Zn-Mg-Cu alloy[J]. Materials Characterization, 2022, 183: 111617.
[7]江福清, 黄继武, 刘赟, 等. 固溶-时效对新型高强高淬透性热挤压Al-Zn-Mg-Cu-Zr合金组织与性能的影响[J]. 金属热处理, 2019, 44(1): 86-90.
Jiang Fuqing, Huang Jiwu, Liu Yun, et al. Effects of solution and aging on microstructure and properties of new high-strength and high-hardenability hot-extruded Al-Zn-Mg-Cu-Zr alloy[J]. Heat Treatment of Metals, 2019, 44(1): 86-90.
[8]叶拓, 唐明, 刘吉兆, 等. 固溶温度对7075铝合金板材组织与力学性能的影响[J]. 金属热处理, 2022, 47(3): 119-123.
Ye Tuo, Tang Ming, Liu Jizhao, et al. Effect of solution temperature on microstructure and mechanical properties of 7075 aluminum alloy sheet[J]. Heat Treatment of Metals, 2022, 47(3): 119-123.
[9]Lei Z, Bi J, Chen Y, et al. Effect of energy density on formability, microstructure and micro-hardness of selective laser melted Sc and Zr modified 7075 aluminum alloy[J]. Powder Technology, 2019, 356: 594-606.
[10]田妮, 韩世达, 周轶然, 等. Sc含量对Al-10Zn-2.5Mg-1.6Cu-0.15Zr铝合金板材组织与力学性能的影响[J]. 中国有色金属学报, 2021, 31(12): 3489-3498.
Tian Ni, Han Shida, Zhou Yiran, et al. Effect of Sc content on microstructure and mechanical properties of Al-10Zn-2.5Mg-1.6Cu-0.15Zr aluminum alloy sheet[J]. The Chinese Journal of Nonferrous Metals, 2021, 31(12): 3489-3498.
[11]Fang H C, Chao H, Chen K H, et al. Effect of Zr, Er and Cr additions on microstructures and properties of Al-Zn-Mg-Cu alloys[J]. Materials Science & Engineering A, 2014, 610: 10-16.
[12]Wang Y, Wu X, Cao L, et al. Effect of trace Er on the microstructure and properties of Al-Zn-Mg-Cu-Zr alloys during heat treatments[J]. Materials Science & Engineering A, 2020, 792: 139807.
[13]Li H Y, Gao Z H, Yin H, et al. Effects of Er and Zr additions on precipitation and recrystallization of pure aluminum[J]. Scripta Materialia, 2013, 68: 59-62.
[14]Wang M, Huang L, Chen K, et al. Influence of minor combined addition of Cr and Pr on microstructure, mechanical properties and corrosion behaviors of an ultrahigh strength Al-Zn-Mg-Cu-Zr alloy[J]. Micron, 2018, 104: 80-88.
[15]黄高仁, 孙乙萌, 张利, 等. 微量Ce对亚快速凝固Al-Zn-Mg-Cu合金组织与性能的影响[J]. 材料工程, 2018, 46(3): 105-111.
Huang Gaoren, Sun Yimeng, Zhang Li, et al. Effect of trace Ce on microstructure and properties of near-rapidly solidified Al-Zn-Mg-Cu alloys[J]. Journal of Materials Engineering, 2018, 46(3): 105-111.