Effect of Oscillation Frequency and Post-weld Heat Treatment on the Properties of 7A52 Aluminum Alloy MIG Welded Joints

LI Shougen; DU Sinuo; QI Shikong; ZENG Caiyou; ZHU Jialei; PAN Jinghao; DUAN Jixin

doi:10.3969/j.issn.1674-6457.2026.06.007

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Journal of Netshape Forming Engineering ›› 2026, Vol. 18 ›› Issue (6) : 66-74. DOI: 10.3969/j.issn.1674-6457.2026.06.007

Joining of New Materials and Dissimilar Materials

Effect of Oscillation Frequency and Post-weld Heat Treatment on the Properties of 7A52 Aluminum Alloy MIG Welded Joints

LI Shougen¹, DU Sinuo¹, QI Shikong¹, ZENG Caiyou^1,*, ZHU Jialei¹, PAN Jinghao¹, DUAN Jixin²

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Abstract

To address the issues of microstructural inhomogeneity and degradation of joint performance in high-strength 7A52 aluminum alloy during MIG welding, the work aims to systematically investigate the effects of torch oscillation frequency and post-weld T6 heat treatment on the microstructural evolution and mechanical properties of welded joints, thereby elucidating their synergistic strengthening mechanism. MIG welding experiments with groove repair were conducted under different oscillation frequencies with 7A52 aluminum alloy, followed by T6 post-weld heat treatment. The joint performance was characterized by optical microscopy, energy-dispersive spectroscopy (EDS), microhardness testing, and tensile testing. The results indicated that oscillation frequency had a significant effect on molten pool flow behavior. With the increasing oscillation frequency, the weld microstructure transformed from columnar grains to equiaxed grains, with significant grain refinement. After T6 heat treatment, strengthening elements in the weld zone were redistributed, leading to an increased number of precipitates with a more uniform distribution, thereby significantly improving the overall mechanical properties of the welded joints. Under the combined condition of an oscillation frequency of 3 Hz and T6 heat treatment, the welded joint exhibited optimal performance, with an average microhardness of 166HV, a peak microhardness of 180.33HV, and a maximum tensile strength of 472.28 MPa. The results demonstrate a pronounced synergistic strengthening effect between oscillation frequency and post-weld heat treatment, providing a theoretical basis for optimizing the welding process of high-performance MIG welded joints of 7A52 aluminum alloy.

Key words

oscillation frequency / 7A52 aluminum alloy / heat treatment / microstructure / mechanical properties

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LI Shougen, DU Sinuo, QI Shikong, ZENG Caiyou, ZHU Jialei, PAN Jinghao, DUAN Jixin. Effect of Oscillation Frequency and Post-weld Heat Treatment on the Properties of 7A52 Aluminum Alloy MIG Welded Joints[J]. Journal of Netshape Forming Engineering. 2026, 18(6): 66-74 https://doi.org/10.3969/j.issn.1674-6457.2026.06.007

References

[1] 姜成云, 朱加雷, 王程远, 等. 不同热输入对7A52铝合金摆动MIG焊接接头组织及性能的影响[J]. 精密成形工程, 2025, 17(7): 145-152.
JIANG C Y, ZHU J L, WANG C Y, et al.Effect of Different Heat Input on Microstructure and Properties of 7A52 Aluminum Alloy Oscillating MIG Welding Joints[J]. Journal of Netshape Forming Engineering, 2025, 17(7): 145-152.
[2] 黄浩, 肖玉斌, 赵飞, 等. 7A52铝合金摆动激光-电弧复合送丝熔覆修复工艺研究[J]. 电焊机, 2025, 55(8): 74-82.
HUANG H, XIAO Y B, ZHAO F, et al.Research on the Oscillating Laser-Arc Hybrid Wire-Feeding Cladding of 7A52 Al Alloy for Repairing[J]. Electric Welding Machine, 2025, 55(8): 74-82.
[3] YE Z, ZHU H Y, WANG S F, et al.Fabricate High- Strength 7075 Aluminum Alloy Joint through Double Pulse MIG Welding Process[J]. Journal of Manufacturing Processes, 2024, 125: 512-522.
[4] RAMIARISON H, BARKA N, PILCHER C, et al.Weldability Improvement by Wobbling Technique in High Power Density Laser Welding of Two Aluminum Alloys: Al-5052 and Al-6061[J]. Journal of Laser Applications, 2021, 33(3): 032015.
[5] FENG D, LI X D, ZHANG X M, et al.The Novel Heat Treatments of Aluminium Alloy Characterized by Multistage and Non-Isothermal Routes: A Review[J]. Journal of Central South University, 2023, 30(9): 2833-2866.
[6] LIU X, WANG C Y, LI X P, et al.Investigation of 7075 Aluminum Alloy TIG Welding Joint Using 7075 Aluminum Alloy Wire before and after Heat Treatment[J]. Materials Research Express, 2023, 10(4): 046512.
[7] JIA X D, FAN Z Y, LUO Z, et al.Impact of Heat Treatment Parameters on the Plastic Properties of 6061 Aluminum Alloy[J]. Materials, 2025, 18(8): 1705.
[8] HU R Z, GUO C, MA M L.A Study on High Strength, High Plasticity, Non-Heat Treated Die-Cast Aluminum Alloy[J]. Materials, 2021, 15(1): 295.
[9] QI Q W, LI M, DUAN Y H, et al.Effect of Solution Heat Treatment on the Microstructure and Microhardness of 7050 Aluminum Alloy[J]. Metals, 2023, 13(11): 1819.
[10] ZHAO J T, JIANG P, GENG S N, et al.Experimental and Numerical Study on the Effect of Increasing Frequency on the Morphology and Microstructure of Aluminum Alloy in Laser Wobbling Welding[J]. Journal of Materials Research and Technology, 2022, 21: 267-282.
[11] LI X Y, SUN G R, REN B Q, et al.Microstructure and Mechanical Properties of 7075 Aluminum Alloy Welded Joints Fabricated by MIG Welding with 7085-Sc Welding Wire[J]. Materials Science and Engineering: A, 2025, 944: 148969.
[12] 杨靖琪, 龚红英, 邱文宇, 等. 单级时效热处理工艺对7075铝合金微观组织及力学性能的影响[J]. 塑性工程学报, 2026, 33(1): 256-262.
YANG J Q, GONG H Y, QIU W Y, et al.Effect of Single Stage Aging Heat Treatment Process on Microstructure and Mechanical Properties of 7075 Aluminum Alloy[J]. Journal of Plasticity Engineering, 2026, 33(1): 256-262.
[13] 张晓波, 秦夏彤, 高翔, 等. 焊后热处理对7075铝合金MIG焊接接头组织性能的影响[J]. 机械工程与自动化, 2026, 55(1): 42-44.
ZHANG X B, QIN X T, GAO X, et al.The Effect of Post Weld Heat Treatment on the Micro Structure and Propertiesof 7075 Aluminum Alloy MIG Welding Joints[J]. Mechanical Engineering & Automation, 2026, 55(1): 42-44.
[14] RAJENDRAN C, SONAR T, IVANOV M, et al.Enhancing Tensile Properties of Pulsed CMT-MIG Welded High Strength AA2014-T6 Alloy Joints: Effect of Post Weld Heat Treatment[J]. International Journal of Lightweight Materials and Manufacture, 2024, 7(2): 344-352.
[15] HUANG J K, CHEN H Z, HE J, et al.Narrow Gap Applications of Swing TIG-MIG Hybrid Weldings[J]. Journal of Materials Processing Technology, 2019, 271: 609-614.
[16] 王志英, 白嘉瑜, 李代龙, 等. MIG摆动电弧对2319铝合金增材制造表面形貌和性能的影响[J]. 焊管, 2025, 48(8): 80-88.
WANG Z Y, BAI J Y, LI D L, et al.Influence of MIG Oscillating Arc on Surface Morphology and Properties of 2319 Aluminum Alloy Additive Manufacturing[J]. Welded Pipe and Tube, 2025, 48(8): 80-88.
[17] 赵云峰, 周禄军, 王鹏飞, 等. 不同惰性气节气下6005A铝合金MIG焊接接头组织演变与力学性能研究[J]. 焊接技术, 2025, 54(8): 37-41.
ZHAO Y F, ZHOU L J, WANG P F, et al.Study on Microstructure Evolution and Mechanical Properties of MIG Welded Joint of 6005A Aluminum Alloy under Different Inert Gas Condition[J]. Welding Technology, 2025, 54(8): 37-41.
[18] KIM Y, CHOI S, KIM Y, et al.Changes in Thermal Properties of 7075 Aluminium Alloy by Aging Heat Treatment[J]. Materials Science and Technology, 2023, 39(10): 1208-1213.
[19] CHIANG M T, CHIU K Y, WU P C, et al.Improvement of the Mechanical Properties of the Diffusion-Bonded 2024 Aluminum Alloy through Post-Weld Heat Treatments[J]. Metals, 2022, 12(10): 1738.
[20] EL GARCHANI F E, LGAZ H, KAYA S, et al. Effects of Heat Treatment on the Corrosion Behavior and Mechanical Properties of Aluminum Alloy 2024[J]. Journal of Materials Research and Technology, 2023, 25: 1355-1363.
[21] DENG A L, CHEN H, ZHANG Y B, et al.Prediction of the Influence of Welding Metal Composition on Solidification Cracking of Laser Welded Aluminum Alloy[J]. Materials Today Communications, 2023, 35: 105556.
[22] 陈宇航, 屈华, 付佳玉, 等. 焊后热处理对2A12铝合金脉冲MIG焊接接头组织和性能的影响[J]. 材料热处理学报, 2026, 47(2): 236-244.
CHEN Y H, QU H, FU J Y, et al.Effect of Post-Weld Heat Treatment on Microstructure and Properties of Pulse MIG Welded Joints of 2A12 Aluminum Alloy[J]. Transactions of Materials and Heat Treatment, 2026, 47(2): 236-244.
[23] JIANG Z, HUA X M, HUANG L J, et al.Double-Sided Hybrid Laser-MIG Welding Plus MIG Welding of 30-mm-Thick Aluminium Alloy[J]. The International Journal of Advanced Manufacturing Technology, 2018, 97(1): 903-913.
[24] CHEN G Y, WANG B, MAO S, et al.Research on the “∞”-Shaped Laser Scanning Welding Process for Aluminum Alloy[J]. Optics & Laser Technology, 2019, 115: 32-41.
[25] WANG H Y, LIU X H, LIU L M.Research on Laser-TIG Hybrid Welding of 6061-T6 Aluminum Alloys Joint and Post Heat Treatment[J]. Metals, 2020, 10(1): 130.

Funding

R&D Program of Beijing Municipal Education Commission (KM202310017006); Key Program of the Joint Fund of the National Natural Science Foundation of China (U22B20127)