Research on Welding Process and Joint Microstructure-properties of Bobbin Tool Friction Stir Weld for 2219 Aluminum Alloy

doi:10.3901/JME.2022.22.250

Abstract

Abstract: Bobbin tool friction stir welding of 8 mm thick 2219 aluminum alloy sheets is carried out, and the influence of welding speed on the microstructure and mechanical properties of the welded joints are investigated. The results show that at the rotational rate is 200 r/min, sound joints can be obtained under the various welding speeds. As the welding speed increases, the heat input decreases,so that the size of the recrystallized grains gradually decreases. The hardness change of 2219 aluminum alloy can be attributed to the distribution of precipitates phase particles and the heterogeneity of grains. The lowest hardness zones are located at the heat-affected zones of the joint. With the increase of welding speed, the lowest hardness and tensile strength of the welded joints increase gradually.The welded joints fracture in the boundary of the HAZ and TMAZ. When the welding speed is 350 mm/min, the tensile strength reaches the maximum value of 335 MPa, which corresponds to 72.8% of that of the base metal.

Key words: bobbin tool friction stir welding, 2219 aluminum alloy, microstructure and mechanical properties

CLC Number:

TG457

ZHANG Hai-feng, HAO Yun-fei, LI Gao-hui, YAN Xu, YANG Hai-feng, ZHOU Li. Research on Welding Process and Joint Microstructure-properties of Bobbin Tool Friction Stir Weld for 2219 Aluminum Alloy[J]. Journal of Mechanical Engineering, 2022, 58(22): 250-257.

References

[1] 何海林. 2219铝合金大型环件组织性能调控方法与工程应用研究[D].长沙:中南大学,2019.HE Hailin. Microstructure and properties of 2219aluminum alloy large ring and its engineering application[D].Changsha:Central South University,2019.
[2] ANDREAS B, THOMAS G, CHRISTOPH P, et al.Characterization of the microstructure in friction stir welds of EN AW-2219 using coincident Doppler-broadening spectroscopy[J].Materials Characterization,2019,149(1):143-152.
[3] 康举,李吉超,冯志操,等. 2219-T8铝合金搅拌摩擦焊接头力学和应力腐蚀性能薄弱区研究[J].金属学报,2016,52(1):60-70.KANG Ju,LI Jizhao,FANG Zhichao,et al. Investigation on mechanical and stress corrosion cracking properties of weakness zone in friction stir welded 2219-T8 Al alloy[J].Acta Metallurgica Sinica,2016,52(1):60-70.
[4] HU Y Y,LIU H J,FUJII H. Improving the mechanical properties of 2219-T6 aluminum alloy joints by ultrasonic vibrations during friction stir welding[J]. Journal of Materials Processing Tech.,2019,271(1):75-84.
[5] MISHRA R S, MA Z Y. Friction stir welding and processing[J]. Materials Science and Engineering R,2005,50(1):1-78.
[6] VIVEK P, LI W Y, ACHILLES V, et al. Recent development in friction stir processing as a solid-state grain refinement technique:Microstructural evolution and property enhancement[J]. Critical Reviews in Solid State and Materials Sciences,2019,44(5):378-426.
[7] XUE P,ZHANG X X,WU L H,et al. Research process on friction stir welding and processing[J]. Acta Metallurgica Sinica,2016,52(10):1222-1238.
[8] CAM G. Friction stir welded structural materials:Beyond Al-alloys[J]. International Materials Reviews, 2011,56(1):1-48.
[9] GUO Q H,DONG X C,HAO M W,et al. Effect of tool probe with a disc at the top on the microstructure and mechanical properties of FSW joints for 6061-T6 aluminum alloy[J]. Journal of Adhesion Science and Technology,2019,33(22):2462-2475.
[10] THOMAS W M,WIESNER C S. Recent developments of FSW technologies:Evaluation of root defects,composite refractory tools for steel joining and one-pass welding of thick sections using self-reacting bobbin tools[C]//8th International Conference on Trends in Welding Research,Pine Mountain,United States. 2008.
[11] 乔亚霞,彭杏娜,张鹏飞,等.国内搅拌摩擦焊技术在输变电领域的应用现状及发展前景[J].焊接,2019(4):34-38,66-67.QIAO Yaqia,PENG Xinna,ZHANG Pengfei,et al.Application and development prospect of friction stir welding technology in power transmission and transformation field in China[J]. Welding&Joining,2019(4):34-38,66-67.
[12] 杨亚楠,刘振邦,仪家良.搅拌摩擦焊技术应用现状与发展趋势[J].工程技术研究,2017(2):57-58.YANG Yanan,LIU Zhenbang,YI Jialiang. Application status and development trend of friction stir welding technology[J]. Engineering Technology and Application,2017(2):57-58.
[13] SKINNER M,EDWARDS R L. Improvements to the FSW process using the self-reacting technology[C]//Materials Science Forum. 2003,426:2849-2854.
[14] 刘朝磊. 6061铝合金双轴肩搅拌摩擦焊工艺及机理研究[D].哈尔滨:哈尔滨工业大学,2015.LIU Chaolei. Research on process and mechanism of selr-reacting friction stir welding for 6061 aluminum alloy[D]. Harbin:Harbin Institute of Technology,2015.
[15] WAN L,HUANG Y X,LV Z L,et al. Effect of self-support friction stir welding on microstructure and microhardness of 6082-T6 aluminum alloy joint[J].Materials and Design,2014,55:197-203.
[16] 张健,李光,李从卿,等. 2219-T4铝合金双轴肩FSW与常规FSW接头性能对比研究[J].焊接,2008(11):50-52.ZHANG Jian,LI Guang,LI Congqing,et al. Comparison of joint properties of AA2219-T4 between conventional FSW and bobbin-tool FSW[J]. Welding&Joining,2008(11):50-52.
[17] ZHANG H T,SONG J Q. Microstructural evolution of aluminum magnesium lap joints welded using MIG process with zinc foil as an interlayer[J]. Materials Letters,2011,65(21-22):3292-3299.
[18] XU W F,LUO Y X,ZHANG W,et al. Comparative study on local and global mechanical properties of bobbin tool and conventional friction stir welded 7085-T7452aluminum thick plate[J]. Journal of Materials Science&Technology,2018,34(1):173-184.
[19] FENG X L,LIU H J,LIPPOLD J C. Microstructure characterization of the stir zone of submerged friction stir processed aluminum alloy 2219[J]. Materials Characterization,2013,82:97-102.
[20] XU W,LIU J,LUAN G,et al. Microstructure and mechanical properties of friction stir welded joints in 2219-T6 aluminum alloy[J]. Mater. Des.,2009,30:3460-3467.
[21] LIU H,ZHANG H,YU L. Effect of welding speed on microstructures and mechanical properties of underwater friction stir welded 2219 aluminum alloy[J]. Material Design,2011,32:1548-1553.
[22] 汤智茂,湛利华,徐永谦,等.时效热处理对2219铝合金搅拌摩擦焊焊缝组织性能的影响[J].塑性工程学报,2021,28(5):134-144.TANG Zhimao,ZHAN Lihua,XU Yongqian,et al. Effect of aging heat treatment on microstructure and properties of friction stir welding seam of 2219 aluminum alloy[J].Journal of Plasticity Engineering,2021,28(5):134-144.
[23] LI J Q, LIU H J. Effects of welding speed on microstructures and mechanical properties of AA2219-T6welded by the reverse dual-rotation friction stir welding[J].The International Journal of Advanced Manufacturing Technology,2013,68(9-12):2071-2083.