skip to main content


Title: Effects of thread interruptions on tool pins in friction stir welding of AA6061

In this paper, effects of pin thread and thread interruptions (flats) on weld quality and process response parameters during friction stir welding (FSW) of 6061 aluminium alloy were quantified. Otherwise, identical smooth and threaded pins with zero to four flats were adopted for FSW. Weldability and process response variables were examined. Results showed that threads with flats significantly improved weld quality and reduced in-plane forces. A three-flat threaded pin led to production of defect-free welds under all examined welding conditions. Spectral analyses of in-plane forces and weld cross-sectional analysis were performed to establish correlation among pin flats, force dynamics and defect formation. Finally, the lowest in-plane force spectra amplitudes were consistently observed for defect-free welds.
 [1] ;  [2] ;  [1]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725; EEC-0437341
Accepted Manuscript
Journal Name:
Science and Technology of Welding and Joining
Additional Journal Information:
Journal Volume: 23; Journal Issue: 2; Journal ID: ISSN 1362-1718
Taylor & Francis
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE; National Science Foundation (NSF)
Contributing Orgs:
Univ. of South Carolina, Columbia, SC (United States)
Country of Publication:
United States
42 ENGINEERING; friction stir welding; unthreaded pin; threaded pin; flats; in-plane forces
OSTI Identifier: