ASSESSMENT OF EFFECTIVE NUGGET SIZE, NUGGET ROTATION AND FAILURE MODE OF FRICTION STIR SPOT WELDS OF AA2219-O ALLOY

Authors

  • Olatunji Oladimeji Ojo 1. Department of Mechanical Engineering, The Federal University of Technology Akure, Ondo State. Nigeria.
  • Taban Emel 2. Department of Mechanical Engineering, Kocaeli University, Turkey

Keywords:

Friction stir spot weld; nugget rotation; nugget size; fracture; Aluminium efficiency

Abstract

Weld nugget is core for the integrity of friction stir spot welds. Based on this understanding, the investigation of nugget size, nugget rotation and weld failure mode of friction stir spot welded aluminium alloy of AA2219-O was examined. Tapered pin and featureless pin-less tools were employed in welding the alloy at varying tool rotational speed, dwell time and shoulder plunge depths. Intense nugget rotation and feeble nugget rotation were observed in pinless and conical pin welds respectively. However, bonded size or nugget size was predominantly controlled by tool rotational speed and plunge depth in both categories of weld; the percentage contributions of plunge depth in pinless and conical pin welds are 83.97% and 41.68% respectively. Conical pin weld failed via nugget shear failure across the ring-like weld nugget whereas nugget pull-out and interfacial weld failures were obtained in pinless weld.

References

Gerlich A., Avramovic-Cingara G., North T.H. (2006): Stir Zone Microstructure and Strain Rate during Al 7075-T6 Friction Stir Spot Welding, Metallurgical and Materials Transactions A Vol. 37A, pp. 2773-2786
Gerlich A., Avramovic-Cingara G., North T.H. (2006): Stir Zone Microstructure and Strain Rate during Al 7075-T6 Friction Stir Spot Welding, Metallurgical and Materials Transactions A, Vol. 37A, pp. 2773-2786
Gerlich A., Yamamoto M., North T.H (2008): Local melting and tool slippage during friction stir spot welding of Al-alloys, Journal of Material Science 43, pp. 2-11; DOI: 10.1007/s10853-007-1791-7
Kanwer S. A., Pandey S., Schaper M., Rajneesh K. (2010): Effect of process parameters on friction stir welding of aluminum alloy 2219-T87, International
Journal of Advanced Manufacturing Technology 50, pp.941–952; DOI: 10.1007/s00170-010-2560-3
Ojo O. O., Taban E., Kaluc E. (2016): Understanding the role of welding parameters and tool profile on the morphology and properties of expelled flash of spot welds, Materials & Design, DOI: 10.1016/j.matdes.2016.07.013
Paidar M., Khodabandeh A., Hamidreza N., Alireza S. R. (2015): An investigation on mechanical and metallurgical properties of 2024-T3 aluminum alloy spot friction welds, International Journal of Advanced Manufacturing Technology, DOI: 10.1007/s00170-015-6997-2
Paidar M., Khodabandeh A., Mahsa L. S. and Morteza T. (2015): Effect of welding parameters (plunge depths of shoulder, pin geometry, and tool rotational speed) on the failure mode and stir zone characteristics of friction stir spot welded aluminum 2024-T3 sheets, Journal of Mechanical Science and Technology 29 (11), pp.4639-4644; DOI: 10.1007/s12206-015-1009-x
Rajakumar S., Balasubramanian V. (2012): Correlation between weld nugget grain size, weld nugget hardness and tensile strength of friction stir welded commercial grade aluminium alloy joints, Materials and Design, vol. 34, pp. 242-251
Sajed M., Bisadi H. (2016): Experimental failure study of friction stir spot welded similar and dissimilar aluminum alloys, Weld World, pp. 60:33-40; DOI: 10.1007/s40194-015-0268-6

Downloads

Published

2019-04-29