Effect of Heat Sink on Mechanical, Metallurgical and Microstructural Characteristics of Friction Stir Spot Welded Dissimilar Al6061 and Al5052 Joints

Authors S. Siddharth1, A. Pradeep2, V. Hemanthkumar3, J. Rajaparthiban4

1Department of Mechanical Engineering, PSN College of Engineering & Technology, Tirunelveli, TN, India

2Department of Mechanical Engineering, Saveetha School of Engineering, SIMATS Chennai, TN, India

3Department of Physics, Bharath Institute of Higher Education & Research, Chennai, TN, India

4Department of Mechanical Engineering, Chennai Institute of Technology, Chennai, TN, India

Е-mail sksmsiddharth1@yahoo.in
Issue Volume 14, Year 2022, Number 6
Dates Received 14 October 2022; revised manuscript received 20 December 2022; published online 27 December 2022
Citation S. Siddharth, A. Pradeep, et al., J. Nano- Electron. Phys. 14 No 6, 06008 (2022)
DOI https://doi.org/10.21272/jnep.14(6).06008
PACS Number(s) 46.55. + d, 81.20.Vj
Keywords Friction stir spot welding, Heat sink, Temperature dissipation, Microstructure (21) , Microhardness (2) .

Friction stir spot welding is a well-known material joining technique for welding similar as well as dissimilar materials. In this welding technique, the operating temperature is retained below the melting point of the workpieces. As the temperature in the weld region is maintained above the recrystallization point and below the melting point, the joining takes place as a severe plastic deformation. It is advantageous as it joins dissimilar materials having unique and different properties as a single welded joint. In this paper, an attempt has been made to use copper material as heat sinks during spot joining of dissimilar Al6061 and Al5052 joints. The presence of Cu heat sinks ensured quick dissipation of frictional heat created in the nugget region. The spot welds cooled faster. When using Cu heat sinks, the cooling rates reduced by 32 %. Tensile properties of Al6061-Al5052 spot joints increased by 7.8 % and the joint microhardness improved by 12.3 %, compared to joints fabricated without heat sink attachment. Intermetallic compounds were not formed, and the grains were less deformed when using heat sinks. Faster cooling times ensured quick changeover of workpieces. The running duration of the welding equipment reduced by 19.3 %, as the joints were prepared faster. Hence the power consumption (energy savings) in a single shift was found to decrease by 11.35 %.

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