Advertisement

Liquid interlayer formation during friction stir spot welding of aluminum/copper

  • Anna Regensburg
  • Franziska Petzoldt
  • Tobias Benss
  • Jean Pierre Bergmann
Research Paper
  • 56 Downloads

Abstract

The fabrication of dissimilar aluminum/copper joints for electrical application raises the challenges for conventional joining technologies. Within the solid-state processes, friction stir welding (FSW) provides numerous advantages to realize different joint configurations, especially by minimizing the heat input and hence the formation of brittle intermetallic phases. However, the joints also have to provide a high contact interface with firm bonding in order to provide a minimal contact resistance. Therefore, joints of 1 mm ENCW004A and EN AW1050A with a controlled melt layer formation were produced by friction stir spot welding (FSSW). By using a pinless tool and the positioning of copper as the upper joining partner, local melt formation at the interface with a eutectic composition was promoted without significant intermixing, resulting in wetting of the aluminum and a contact area increase. The rotational speed was varied between 1800–2400 rpm, in which range samples with up to 300-μm-thick melt layers were produced. The wetting effect at the interface shows a positive influence on the shear strength with ductile failure behavior even at high layer thickness. The microstructural composition at the interface showed a eutectic composition for small layer thickness and an inhomogeneous composition with hypo- and hypereutectic solidification structures for higher thickness values. However, the formation of intermetallic compounds other than CuAl2 was mostly inhibited by the short process times and high cooling rate.

Keywords

Friction stir welding Solidification Electric contacts Lap joints Dissimilar materials 

Notes

Acknowledgements

The IGF Project No. 19.036 B of the research association “Schweißen und verwandte Verfahren e.V.” of the DVS, Aachener Straße 172, 40223 Düsseldorf, was, on the basis of a resolution of the German Bundestag, promoted by the Federal Ministry for Economic Affairs and Energy via AiF within the framework of the program for the promotion of joint industrial research and development (IGF). The authors thank all the participants for the support.

Funding information

The authors thank all the participants for the funding.

Supplementary material

40194_2018_620_MOESM1_ESM.rar (4.7 mb)
ESM 1 (RAR 4764 kb)

References

  1. 1.
    Braunovic M, Aleksandrov N (1994) Intermetallic compounds at aluminum-to-copper electrical interfaces: effect of temperature and electric current. IEEE Trans Compon Packag Manuf Technol Part A 17:78–85CrossRefGoogle Scholar
  2. 2.
    Abbasi M, Karimi Taheri A, Salehi MT (2001) Growth rate of intermetallic compounds in Al/Cu bimetalproduced bycold roll welding process. J Alloys Compd 319:233–241CrossRefGoogle Scholar
  3. 3.
    Marya M, Marya S, Priem D (2005) On the characteristics of electromagnetic welds between aluminium and other metals and alloys. Welding in the World 49(5):74–84CrossRefGoogle Scholar
  4. 4.
    Zhao YY, Li D, Zhang YS (2013) Effect of welding energy on interface zone of Al–Cu ultrasonic welded joint. Sci Technol Weld Join 18(4):354–360CrossRefGoogle Scholar
  5. 5.
    Bisadi H, Tavakoli A, Tour Sangsaraki M, Tour Sangsaraki M (2013) The influences of rotational and welding speeds on microstructures and mechanical properties of friction stir welded Al5083 and commercially pure copper sheets lap joints. Materials Design 43:80–88CrossRefGoogle Scholar
  6. 6.
    Saeid T, Abdollah-Zadeh A, Sazgari B (2010) Weldability and mechanical properties of dissimilar aluminum–copper lap joints made by friction stir welding. J Alloys Compd 490:652–655CrossRefGoogle Scholar
  7. 7.
    Schürer R, Weigl M, Döhner J, Bergmann JP (2015) Robotergestütztes Rührreibschweißen als flexibleLösung in der modernen Fertigung. DVS Congress, NürnbergGoogle Scholar
  8. 8.
    Firouzdor V, Kou S (2012) Al-to-Cu friction stir lap welding. Metall Mater Trans A 43A:303–315CrossRefGoogle Scholar
  9. 9.
    Mubiayi MP, Akinlabi ET (2015) Friction stir spot welding between copper and aluminium: microstructural evolution. Proceedings of the International MultiConference of Engineers and Computer Scientists, Vol 2Google Scholar
  10. 10.
    Heideman R, Johnson C, Kou S (2010) Metallurgical analysis of Al/Cu friction stir spot welding, Scienceand Technology of Welding and Joining, Vol. 15, Issue 7Google Scholar
  11. 11.
    Galvão I, Verdera D, Gesto D, Loureiro A, Rodrigues DM (2013) Influence of aluminium alloy type on dissimilar friction stir lap welding of aluminium to copper. J Mater Process Technol 213(11):1920–1928CrossRefGoogle Scholar
  12. 12.
    Gündüz M, Cadirli E Directional solidification of aluminium–copper alloys. Mater Sci Eng 327:167–185Google Scholar
  13. 13.
    Wu MF, Yu C, Pu J (2008) Study on microstructures and grain boundary penetration behaviours in contact reactive brazing joints of 6063Al alloy. Mater Sci Technol 24:1422–1426CrossRefGoogle Scholar
  14. 14.
    Han Y, Ben L, Yao J, Feng S, Wu C (2015)Investigation on the interface of Cu/Al couples during isothermal heating, Int J Miner Metall Mater, Volume 22Google Scholar
  15. 15.
    Yang YK, Dong H, Kou S (2008) Liquation tendency and liquid-film formation in friction stir spot welding. Weld J 87:202–211Google Scholar
  16. 16.
    Shen J, Suhuddin UFH, Barbosa MEB, dos Santos JF (2014) Eutectic structures in friction spot welding joint of aluminum alloy to copper. Appl Phys Lett 104:191901CrossRefGoogle Scholar
  17. 17.
    Sun SH, Li J, Zhao YW, Zhao HL, Xu R, Liu RP (2008) Study on eutectic transformation in Al-Cu alloys under 5 GPa pressure condition. Phys Test Chem Anal Part A 44:465–466Google Scholar
  18. 18.
    Xu B, Tong WP, Liu CZ, Zhang H, Zuo L, He JC (2011) Effect of high magnetic field on growth behavior of compound layers during reactive diffusion between solid cu and liquid al. J Mater Sci Technol 27:856–860CrossRefGoogle Scholar
  19. 19.
    Kaya H (2012) Dependence of electrical resistivity on temperature and composition of Al–Cu alloys. Mater Res Innov 16(3):224–229CrossRefGoogle Scholar
  20. 20.
    Clarke AJ, Tourret D, Imhoff SD, Gibbs PJ, Fezzaa K, Cooley JC, Lee W, Deriy A, Patterson BM, Papin PA, Clarke KD, Field R, Smith JL (2015) X-ray imaging and controlled solidification of Al-Cu alloys toward microstructures by design. Adv Eng Mater 2015 17(4):454–459CrossRefGoogle Scholar
  21. 21.
    Xu H, Liu C, Silberschmidt VV, Pramana SS, White TJ, Chen Z, Acoff VL (2011) Behavior of aluminum oxide, intermetallics and voids in Cu–Al wire bonds. Acta Mater 59:5661–5673CrossRefGoogle Scholar

Copyright information

© International Institute of Welding 2018

Authors and Affiliations

  • Anna Regensburg
    • 1
  • Franziska Petzoldt
    • 1
  • Tobias Benss
    • 1
  • Jean Pierre Bergmann
    • 1
  1. 1.Department of Production TechnologyTechnische Universität IlmenauIlmenauGermany

Personalised recommendations