Effect of pin tool profile on mechanical and metallurgical properties in friction stir spot welding of pure copper

Ahmed Mahgoub, Neçar Merah, Abdelaziz Bazoune, Fadi Al-Badour

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

In this paper, the influence of thread feature on mechanical and metallurgical properties of friction stir spot weldments is studied. Two pin tools, plain cylindrical and threaded cylindrical, having the same size are used to produce lap joints by friction stir spot welding (FSSW) of commercially pure copper. All experiments have been performed under the same welding parameters. The results revealed that joints produced with threaded pin tool have more than double the tensile shear strength of those produced by plain cylindrical pin. Moreover, the samples that were FSS welded with threaded pin tool failed in a plug failure mode, which is a desirable ductile failure mode. On the other hand, the weldments that were produced using plain cylindrical pin tool failed in interfacial failure mode or shear fracture mode. Effective upper sheet thickness analysis showed upward hook formation and less effective upper sheet thickness, which indicate better material mixing in the case of threaded pin tool. Furthermore, the transition bonding region was found to be very narrow in the case of plain tool while that of the threaded pin tool showed a transition region that is almost equal to complete bonding region, indicating gradual change from unbonded to complete bond; resulting in the above observed higher strength. Scanning electron microscopy analysis of the hook formation region revealed that, contrary to the weldments performed by plain pin tool, which showed the presence of large voids around the hook region, weldments performed with threaded pins were free of defects.

Original languageEnglish
Title of host publication2017 8th International Conference on Mechanical and Aerospace Engineering, ICMAE 2017
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages381-384
Number of pages4
ISBN (Electronic)9781538633052
DOIs
StatePublished - 14 Sep 2017

Publication series

Name2017 8th International Conference on Mechanical and Aerospace Engineering, ICMAE 2017

Bibliographical note

Publisher Copyright:
© 2017 IEEE.

Keywords

  • FSSW
  • FSW failure mode
  • defects
  • hook
  • pin tool feature

ASJC Scopus subject areas

  • Mechanical Engineering
  • Ceramics and Composites
  • Metals and Alloys
  • Aerospace Engineering

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