T2纯铜快速冷却搅拌摩擦焊缝微观组织和力学性能研究

doi:10.3901/JME.2022.24.094

机械工程学报 ›› 2022, Vol. 58 ›› Issue (24): 94-101.doi: 10.3901/JME.2022.24.094

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T2纯铜快速冷却搅拌摩擦焊缝微观组织和力学性能研究

许楠, 陈磊, 刘坤, 刘露涛, 宋亓宁, 包晔峰

河海大学机电工程学院常州 213022

收稿日期:2022-03-15 修回日期:2022-10-03 出版日期:2022-12-20 发布日期:2023-04-03
通讯作者: 许楠(通信作者),男,1985年出生,博士,教授。主要研究方向为先进材料搅拌摩擦焊接及加工。E-mail:xunan@hhu.edu.cn
作者简介:许楠(通信作者),男,1985年出生,博士,教授。主要研究方向为先进材料搅拌摩擦焊接及加工。E-mail:xunan@hhu.edu.cn
基金资助:
江苏省自然科学基金（BK20211076）、国家自然科学基金（51805145）和江苏省高校“青蓝工程”资助项目。

Research on Microstructure and Mechanical Properties of Rapid Cooling Friction Stir Welded T2 Copper Joint

XU Nan, CHEN Lei, LIU Kun, LIU Lutao, SONG Qining, BAO Yefeng

College of Mechanical and Electrical Engineering, Hohai University, Changzhou 213022

Received:2022-03-15 Revised:2022-10-03 Online:2022-12-20 Published:2023-04-03

摘要/Abstract

摘要： 由于焊后余热带来的退火软化效应，T2纯铜常规搅拌摩擦焊（Friction stir welding，FSW）焊缝通常会出现位错密度降低和晶粒长大的现象，其屈服强度普遍较低。为消除焊后退火效应并改善力学性能，采用液态CO₂同步快速冷却FSW工艺对2 mm的T2纯铜进行焊接。利用光学显微镜、电子背散射衍射、透射电子显微镜、显微硬度测试以及拉伸试验对焊缝的微观组织、力学性能和加工硬化行为进行研究。结果表明，纯铜FSW焊缝的晶粒细化机制主要为不连续动态再结晶、连续动态再结晶和孪晶诱导几何动态再结晶。快速冷却FSW纯铜焊缝呈现具有纳米孪晶和高位错密度的细晶结构，在加工硬化第Ⅲ阶段表现出较大的加工硬化率。在第Ⅳ阶段，纳米孪晶为位错增殖提供储存空间，使加工硬化率降低并改善塑性。和常规FSW相比，快速冷却FSW焊缝的屈服强度和断后伸长率分别提高了31.1%和25.7%。本文提出的液态CO₂同步快速冷却FSW工艺通过改善焊接热循环可在焊缝中制备异质细晶结构，有助于提高焊缝的屈服强度并使其表现出良好的强塑性匹配。

关键词: 搅拌摩擦焊, 纯铜, 微观组织, 力学性能, 加工硬化行为

Abstract: Conventional friction stir welded (FSW) T2 copper joint usually exhibits a low yield strength due to the decreased dislocation density and coarsened grain size caused by post-annealing effect. To eliminate the post-annealing effect and improve mechanical properties, 2-mm-thick T2 copper plates was subjected to liquid CO₂ assisted rapid cooling FSW technology. Microstructural evolution, mechanical properties, and strain hardening behavior of the welds are investigated by optical microscopy, electron backscatter diffraction, transmission electron microscopy, microhardness measurement, and tensile tests. The results show that the grain refinement mechanism of the FSW copper weld is attributed to discontinuous dynamic recrystallization, continuous dynamic recrystallization, and twinning-induced geometric dynamic recrystallization. The rapid cooling FSW weld exhibits a fine grain structure with nano-twins and massive dislocations, and thus it had a high strain hardening rate at stage Ⅲ of strain hardening behavior. During the stage Ⅳ, the nano-twins provide enough storage space for dislocation movement, resulted in reduced strain hardening rate and improved ductility. Compared with the conventional FSW, the yield strength and elongation of rapid cooling FSW weld increase by 31.1% and 25.7%, respectively. The liquid CO₂ assisted rapid cooling FSW technology proposed can prepare heterogeneous fine grain structure in the welded joint by improving the thermal cycle, which is helpful to improve the yield strength. A welded joint with good matching of strength and ductility is achieved by using this advanced FSW technology.

Key words: friction stir welding, copper, microstructure, mechanical properties, strain hardening behavior

中图分类号:

TG453

许楠, 陈磊, 刘坤, 刘露涛, 宋亓宁, 包晔峰. T2纯铜快速冷却搅拌摩擦焊缝微观组织和力学性能研究[J]. 机械工程学报, 2022, 58(24): 94-101.

XU Nan, CHEN Lei, LIU Kun, LIU Lutao, SONG Qining, BAO Yefeng. Research on Microstructure and Mechanical Properties of Rapid Cooling Friction Stir Welded T2 Copper Joint[J]. Journal of Mechanical Engineering, 2022, 58(24): 94-101.

参考文献

[1] EBRAHIMI M, PAR M A.Twenty-year uninterrupted endeavor of friction stir processing by focusing on copper and its alloys[J].Journal of Alloys and Compounds, 2019, 781:1074-1090.
[2] AKBARI MOUSAVI S A A, NIKNEJAD S T.An investigation on microstructure and mechanical properties of Nd:YAG laser beam weld of copper beryllium alloy[J].Metallurgical and Materials Transactions A, 2009, 40(6):1469-1478.
[3] SUZUKI Y, OGURA T, TAKAHASHI M, et al.Low-current resistance spot welding of pure copper using silver oxide paste[J].Materials Characterization, 2014, 98:186-192.
[4] 张昌青, 秦卓, 荣琛, 等.H62黄铜超薄板微搅拌摩擦焊接热机特征与接头组织性能[J].机械工程学报, 2020, 56(12):65-72.ZHANG Changqing, QIN Zhuo, RONG Chen, et al.Thermo-mechanical characteristics and microstructure and properties of micro-stir friction welding of H62 brass ultrathin plate[J].Journal of Mechanical Engineering, 2020, 56(12):65-72.
[5] 杨超, 王英君, 徐艳利, 等.含Sc高强铝合金薄板TIG焊与FSW接头组织与性能对比研究[J].机械工程学报, 2020, 56(6):221-228.YANG Chao, WANG Yingjun, XU Yanli, et al.Microstructure and mechanical properties of TIG and friction stir welded joints of Sc-contained high strength aluminum alloy sheet[J].Journal of Mechanical Engineering, 2020, 56(6):221-228.
[6] SUN Y F, FUJII H.Investigation of the welding parameter dependent microstructure and mechanical properties of friction stir welded pure copper[J].Materials Science and Engineering:A, 2010, 527(26):6879-6886.
[7] KHODAVERDIZADEH H, HEIDARZADEH A, SAEID T.Effect of tool pin profile on microstructure and mechanical properties of friction stir welded pure copper joints[J].Materials & Design, 2013, 45:265-270.
[8] KOCKS U F, MECKING H.Physics and phenomenology of strain hardening:the FCC case[J].Progress In Materials Science, 2003, 48(3):171-273.
[9] KHODAVERDIZADEH H, MAHMOUDI A, HEIDARZADEH A, et al.Effect of friction stir welding (FSW) parameters on strain hardening behavior of pure copper joints[J].Materials & Design, 2012, 35:330-334.
[10] XU Nan, UEJI R, FUJII H.Enhanced mechanical properties of 70/30 brass joint by rapid cooling friction stir welding[J].Materials Science and Engineering:A, 2014, 610:132-138.
[11] WANG Yanfei, AN Jian, YIN Kun, et al.Ultrafine-grained microstructure and improved mechanical behaviors of friction stir welded Cu and Cu-30Zn joints[J].Acta Metallurgica Sinica (English Letters), 2018, 31(8):878-886.
[12] HUANG K, LOGE R E.A review of dynamic recrystallization phenomena in metallic materials[J].Materials & Design, 2016, 111:548-574.
[13] XU Nan, SONG Qining, BAO Yefeng.Investigation on microstructure development and mechanical properties of large-load and low-speed friction stir welded Cu-30Zn brass joint[J].Materials Science and Engineering:A, 2018, 726:169-178.
[14] XU Nan, SONG Qining, BAO Yefeng.Improvement of microstructure and mechanical properties of C44300 tin brass subjected to double-pass rapid cooling friction stir welding[J].Journal of Alloys and Compounds, 2020, 834:155052.
[15] MIRONOV S, SATO Y S, KOKAWA H.Microstructural evolution during friction stir-processing of pure iron[J].Acta Materialia, 2008, 56(11):2602-2614.
[16] XU Nan, SONG Qining, BAO Yefeng, et al.Achieving good strength-ductility synergy of friction stir welded Cu joint by using large load with extremely low welding speed and rotation rate[J].Materials Science and Engineering:A, 2017, 687:73-81.
[17] XU N, CHEN L, FENG R N, et al.Recrystallization of Cu-30Zn brass during friction stir welding[J].Journal of Materials Research and Technology, 2020, 9(3):3746-3758.
[18] LIU F C, NELSON T W.In-situ grain structure and texture evolution during friction stir welding of austenite stainless steel[J].Materials & Design, 2017, 115:467-478.
[19] WANG Wen, YUAN Shengnan, QIAO Ke, et al.Microstructure and nanomechanical behavior of friction stir welded joint of 7055 aluminum alloy[J].Journal of Manufacturing Processes, 2021, 61:311-321.
[20] FONDA R W, KNIPLING K E.Texture development in friction stir welds[J].Science and Technology of Welding and Joining, 2011, 16:288-294.
[21] LIU X C, SUN Y F, NAGIRA T, et al.Strain rate dependent micro-texture evolution in friction stir welding of copper[J].Materialia, 2019, 6:100302.
[22] 许楠, 冯若男, 宋亓宁, 等.微观组织对镁合金FSW焊缝应变硬化行为的影响[J].焊接学报, 2020, 41(11):7-12.XU Nan, FENG Ruonan, SONG Qining, et al.Effects of microstructure on strain hardening behavior of friction stir welded magnesium alloy[J].Transactions of The China Welding Institution, 2020, 41(11):7-12.
[23] CHEN X H, LU L.Work hardening of ultrafine-grained copper with nanoscale twins[J].Scripta Materialia, 2007, 57(2):133-136.
[24] ROLLETT A D, KOCKS U F.A review of the stages of work hardening[J].Solid State Phenomena, 1993, 35-36:1-18.
[25] LU Lei, SHEN Yongfeng, CHEN Xianhua, et al.Ultrahigh strength and high electrical conductivity in copper[J].Science, 2004, 304:422-426.
[26] LU K, LU L, SURESH S.Strengthening materials by engineering coherent internal boundaries at the nanoscale[J].Science, 2009, 324:349-352.
[27] ZHU Ting, LI Ju, SAMANTA A, et al.Interfacial plasticity governs strain rate sensitivity and ductility in nanostructured metals[J].Proceedings of the National Academy of Sciences of the United States of America, 2007, 104(9):3031-3036.

T2纯铜快速冷却搅拌摩擦焊缝微观组织和力学性能研究

Research on Microstructure and Mechanical Properties of Rapid Cooling Friction Stir Welded T2 Copper Joint

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