Journal of Materials Engineering and Performance

, Volume 27, Issue 3, pp 1378–1386 | Cite as

Nugget Structure Evolution with Rotation Speed for High-Rotation-Speed Friction-Stir-Welded 6061 Aluminum Alloy

  • H. J. Zhang
  • M. Wang
  • Z. Zhu
  • X. Zhang
  • T. Yu
  • Z. Q. Wu


High-rotation-speed friction stir welding (HRS-FSW) is a promising technique to reduce the welding loads during FSW and thus facilitates the application of FSW for in situ fabrication and repair. In this study, 6061 aluminum alloy was friction stir welded at high-rotation speeds ranging from 3000 to 7000 rpm at a fixed welding speed of 50 mm/min, and the effects of rotation speed on the nugget zone macro- and microstructures were investigated in detail in order to illuminate the process features. Temperature measurements during HRS-FSW indicated that the peak temperature did not increase consistently with rotation speed; instead, it dropped remarkably at 5000 rpm because of the lowering of material shear stress. The nugget size first increased with rotation speed until 5000 rpm and then decreased due to the change of the dominant tool/workpiece contact condition from sticking to sliding. At the rotation speed of 5000 rpm, where the weld material experienced weaker thermal effect and higher-strain-rate plastic deformation, the nugget exhibited relatively small grain size, large textural intensity, and high dislocation density. Consequently, the joint showed superior nugget hardness and simultaneously a slightly low tensile ductility.


high-rotation-speed friction stir welding macro- and microstructure nugget zone rotation speed 



The authors are grateful to be supported by National Natural Science Foundation of China (Grant No. 51505471) and Innovation Fund from Youth Innovation Promotion Association Chinese Academy of Sciences (Grant No. 2015162).


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Copyright information

© ASM International 2018

Authors and Affiliations

  • H. J. Zhang
    • 1
    • 2
  • M. Wang
    • 2
  • Z. Zhu
    • 2
  • X. Zhang
    • 2
  • T. Yu
    • 2
  • Z. Q. Wu
    • 2
  1. 1.School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdaoChina
  2. 2.State Key Laboratory of RoboticsShenyang Institute of Automation Chinese Academy of SciencesShenyangChina

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