形变时效对Al-4.0Cu-1.0Li-(Zn)合金的时效硬化和晶间腐蚀的影响

形变时效对Al-4.0Cu-1.0Li-(Zn)合金的时效硬化和晶间腐蚀的影响

杨 明，赵新奇*，张 松，伍翠兰

（湖南大学 材料科学与工程学院，湖南 长沙 410082）

摘 要 本文采用透射电镜和扫描电镜观察以及硬度测试等手段，研究了形变时效对Al-4.0Cu-1.0Li-(Zn)合金的时效硬化和晶间腐蚀的影响。结果表明：Al-4.0Cu-1.0Li-Zn合金中的Zn元素主要存在T1相中，Zn元素的添加使晶内T1相直径减小，数量密度变大，分布更加弥散，晶界处T1相由连续变为不连续状态，合金的硬度和抗腐蚀性能提高。形变时效引入预变形量变大，晶内T1相直径尺寸减小，数量密度增加，分布更加弥散，同时抑制晶内δ′/θ′/δ′复合相的析出，提高Al-4.0Cu-1.0Li-(Zn)合金的硬度，加快时效硬化响应速率，而且晶界处无析出带（PFZ）的宽度变窄，合金的抗腐蚀性能提高。添加Zn和引入形变时效的T8工艺协同作用不仅提高Al-4.0Cu-1.0Li-(Zn)合金硬度，增强合金的时效硬化，而且提高合金的抗腐蚀性能。

关键词 Al-Cu-Li合金；形变时效；时效硬化；晶间腐蚀

中图分类号：TG146.21；TG156.9；TG113；TG115.21＋5.3 文献标识码：A Doi:10.3969/j.issn.1000-6281.2025.02.006

Effects of thermo-mechanical treatment on the age hardening and intergranular corrosion of Al-4.0Cu-1.0Li-(Zn) alloy

YANG Ming, ZHAO Xinqi*, ZHANG Song, WU Cuilan

(College of Materials Science and Engineering, Hunan University, Changsha Hunan 410082, China)

Abstract The effect of thermo-mechanical treatment on the age hardening and intergranular corrosion of Al-4.0Cu-1.0Li-(Zn) alloy was investigated using transmission electron microscopy, scanning electron microscopy, hardness test and intergranular corrosion test. The results showed that Zn was incorporated into T1 precipitates, reducing the diameter of intracrystalline T1 precipitates, increasing the quantity density, and causing a more diffuse distribution. As a result, intergranular T1 precipitates distributed discontinuously rather than continuously. The hardness and corrosion properties of the alloys were improved. With increasing deformation from thermo-mechanical treatment, the diameter of the intracrystalline T1 precipitates decreased, their quantity density increased, and the distribution was even more diffuse. In addition, the precipitation of the δ′/θ′/δ′ composite phase was inhibited, leading to an increase in the hardness of alloy and an accelerated age hardening response. Moreover, the width of the precipitate-free zone (PFZ) narrowed, improving the corrosion resistance of alloy. The synergistic effects of adding Zn and the thermo-mechanical treatment under the T8 process not only improved the hardness and age hardening of the Al-4.0Cu-1.0Li-(Zn) alloy but also enhanced its corrosion resistance.

Keywords Al-Cu-Li alloy; thermo-mechanical treatment; age hardening; intergranular corrosion

[1] RIOJA R J. Fabrication methods to manufacture isotropic Al-Li alloys and products for space and aerospace applications [J]. Materials Science and Engineering: A, 1998, (1): 100-107.

[2] RIOJA R J, LIU J. The evolution of Al-Li base products for aerospace and space applications (Article) [J]. Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, 2012, 43 (9): 3325-3337.

[3] HUANG J C, ARDELL A J. Addition rules and the contribution of δ' precipitates to strengthening of aged Al-Li-Cu alloys [J]. Acta Metallurgica, 1988, 36(11): 2995-3006.

[4] GAO Z, CHEN J H, DUAN S Y, et al. Complex precipitation sequences of Al-Cu-Li-(Mg) alloys characterized in relation to thermal ageing processes [J]. Acta Metallurgica Sinica, 2016, 29(1): 94-103.

[5] DUAN S Y, WU C L, GAO Z, et al. Interfacial structure evolution of the growing composite precipitates in Al-Cu-Li alloys [J]. Acta Materialia, 2017, 129(1): 352-360.

[6] LI J F, YE Z H, LIU D Y, et al. Influence of pre-deformation on aging precipitation behavior of three Al-Cu-Li alloys [J]. Acta Metallurgica Sinica, 2017, 30(2): 133-145.

[7] LÜ Y, MENG X Z, DONG Z H, et al. Localized corrosion evolution associated with intermetallic particles in Al-Cu-Li alloys [J]. Materials Characterization, 2023, 204: 113144.

[8] JIANG B, WANG H, TIAN Y, et al. Effects of aging time on corrosion behavior of an Al-Cu-Li alloy [J]. Corrosion Science, 2020, 173: 108759.

[9] LIN Y, LU C, WEI C Y, et al. Effect of aging treatment on microstructures, tensile properties and intergranular corrosion behavior of Al-Cu-Li alloy [J]. Materials Characterization, 2018, 141: 163-168.

[10] 龚小康, 袁欣, 席海辉, 等. 时效温度和Ag对Al-Zn-Mg合金力学性能与微观结构的影响 [J]. 电子显微学报, 2023, 42(2): 143-152.

[11] LI J F, BIRBILIS N, LIU D Y, et al. Intergranular corrosion of Zn-free and Zn-microalloyed Al–xCu–yLi alloys [J]. Corrosion Science, 2016, 105: 44-57.

[12] 李劲风, 宁红, 刘丹阳, 等. Al-Cu-Li系铝锂合金的合金化与微合金化 [J]. 中国有色金属学报, 2021, 31: 258-279.

[13] HUANG B P, ZHENG Z Q. Independent and combined roles of trace Mg and Ag additions in properties precipitation process and precipitation kinetics of Al-Cu-Li(Mg)-(Ag)-Zr-Ti alloys [J]. Acta Materialia, 1998, 46(12): 4381-4393.

[14] GUMBMANN E, LEFEBVRE W, DE G, et al. The effect of minor solute additions on the precipitation path of an Al-Cu-Li alloy [J].Acta Materialia, 2016, 115(16): 104-114.

[15] LIU D Y, LI J F, MA Y L, et al. A closer look at the role of Zn in the microstructure and corrosion of an Al-Cu-Li alloy [J]. Corrosion Science, 2018, 145: 220-231.

[16] 高珍, 陈江华, 刘吉梓, 等. Al-Cu-Li合金中T1相的演变规律研究 [J]. 电子显微学报, 2012, (4): 308-314.

[17] 方磊, 赵新奇, 陈江华, 等. Al-Zn-Mg基合金多级时效不同热处理阶段的析出行为研究 [J]. 电子显微学报, 2012, 31(3): 202-210.

[18] 王芝秀, 章宇豪, 陈天宇, 等. 时效对冷轧Al-Cu-Li合金拉伸性能及晶间腐蚀敏感性的影响 [J]. 中国有色金属学报, 2022, 32(10): 2909-2919.

[19] WANG X Y, LI G, HE Q Y, et al. Intergranular corrosion of an Al-Cu-Li alloy: The influence from grain structure [J]. Corrosion Science, 2023, 211: 110845.

[20] MUÑOZ-MORRIS M A, MORRIS D G. Severe plastic deformation processing of Al-Cu-Li alloy for enhancing strength while maintaining ductility [J]. Scripta Materialia, 2010, 63(3): 304-307.

[21] RODGERS B I, PRANGNELL P B. Quantification of the influence of increased pre-stretching on microstructure-strength relationships in the Al-Cu-Li alloy AA2195 [J]. Acta Materialia, 2016, 108: 55-67.

[22] XIE Y K, LIU SH D, GUO X B, et al. Enhancing the strength of Sc-containing Al-Cu-Li alloys by modifying the precipitation behavior through plastic deformation and heat treatment [J]. Materials Characterization, 2024, 207: 113558.

[23] 邹富强, 李石勇, 伍翠兰, 等. 形变时效对Al-2.4Cu-0.9Li-0.7Mg合金的显微组织和力学性能的影响 [J]. 电子显微学报, 2019, 38(6): 623-631.

[24] National standard of the People’s Republic of China[P]. GB/T 7998-2005, Test Method of Intergranular Corrosion of Aluminum Alloy, 2005.

[25] MA Y, ZHOU X, HUANG W, et al. Localized corrosion in AA2099-T83 aluminum-lithium alloy: The role of intermetallic particles [J]. Materials Chemistry and Physics, 2015, 161: 201-210.

[26] LAVERNIA E J, SRIVATSAN T S, MOHAMED F A. Strength, deformation, fracture behaviour and ductility of aluminium-lithium alloys [J]. Journal of Materials Science, 1990, 25: 1137-1158.

[27] GUMBMANN E, LEFEBVRE W, DE G, et al. The effect of minor solute additions on the precipitation path of an Al-Cu-Li alloy [J]. Acta Materialia, 2016, 115(16): 104-114.

[28] LI S Y, WANG Q, CHEN J H, et al. The effect of thermo-mechanical treatment on the formation of T1 phase and δ′/θ′/δ′ composite precipitate in an Al-Cu-Li-Mg alloy [J]. Materials Characterization, 2021, 176: 111123.