EXPERIMENTAL INVESTIGATION OF MECHANICAL AND METALLURGICAL PROPERTIES IN FRICTION STIR SPOT WELDING OF DISSIMILAR AA6061-T6 TO COPPER
Keywords:
Friction Stir Spot Welding,, Dissimilar Welding, Welding Parameters, AA6061-T6, CopperAbstract
In this study, the effects of important parameters of the FSSW process, rotational speed and dwell time, have been investigated on mechanical and metallurgical properties of dissimilar AA6061-T6 to the pure copper welded joint. In addition, the results were compared with the similar Al-Al and Cu-Cu welded joints. The results indicate that an increase in the rotational speed from 1250 to 1600 rpm and dwell time from 5 to 10 seconds improves the tensile and flexural strength of all the welded samples. Furthermore, at rotational speeds lower than 1250 rpm, due to reduced frictional heat generation, and above 1600 rpm, due to excessive heat production, the quality of the joints decreases. In this welding process, the amount of frictional heat generated directly affects the metallurgical structure, hardness of different welding zones, and intermetallic formations formed. The microstructure and the microhardness studies reveal that different welding parameters lead to the formation of fine grains and recrystallization in the stir zone and other regions with an increase in rotational speed and dwell time. This phenomenon is a result of the heat generated by friction and severe material deformation during welding. The refinement of grains contributes to increasing the hardness and strength. Moreover, the hardness analysis of the welded regions shows that the dissolution and growth of precipitates in the weld metal and its vicinity create a weaker region compared to the base metal, resulting in a decrease in hardness relative to the base metal.
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M. M. Z. Ahmed, M. M. E.-S. Seleman, Z. A. Zidan, R. M. Ramadan, S. A. and N. A. Alsaleh, "Microstructure and Mechanical Properties of Dissimilar Friction Stir Welded AA2024-T4/AA7075-T6 T-Butt Joints," Metals, vol. 11, no. 1, p. 128, 2021. DOI: 10.3390/met11010128.
J. M. Piccini and H. G. Svoboda, "Effect of the Tool Penetration Depth in Friction Stir Spot Welding (FSSW) of Dissimilar Aluminium Alloys," Procedia Materials Science, vol. 9, pp. 868-877, 2015. DOI: 10.1016/j.mspro.2015.04.147.
K. Mehta and V. J. Badheka, "A review on dissimilar friction stir welding of copper to aluminium: Process, properties, and variants," Materials and Manufacturing Processes, vol. 31, no. 3, pp. 233-254, 2016. DOI: 10.1080/10426914.2015.1025971.
S. Dourandish, S. M. Mousavizade, H. R. Ezatpour, and G. R. Ebrahimi, "Microstructure, mechanical properties and failure behaviour of protrusion friction stir spot welded 2024 aluminium alloy sheets," Science and Technology of Welding and Joining, vol. 22, no. 4, pp. 295-307, 2017. DOI: 10.1080/13621718.2017.1386759.
H. A. Derazkola, H. Rahmani, M. Habibnia, and M. B. Limoie, "The feasibility study on AA7075 T-joint via friction stir welding process," Iranian Journal of Manufacturing Engineering, vol. 7, no. 1, pp. 21-32, 2016.
D. Zhang and T. Shibayanagi, "Material flow during friction stir spot welding of dissimilar Al2024/Al materials," Materials Science and Technology, vol. 31, no. 9, pp. 1077-1087, 2015. DOI: 10.1179/1743284714Y.0000000674.
N. Pathak, K. Bandyopadhyay, M. Sarangi, and S. K. Panda, "Microstructure and mechanical performance of friction stir spot-welded aluminum-5754 sheets," Journal of Materials Engineering and Performance, vol. 22, no. 1, pp. 131-144, 2013. DOI: 10.1007/s11665-012-0244-x.
M. Paidar, A. Khodabandeh, H. Najafi, and A. S. Rouh-aghdam, "Effects of the tool rotational speed and shoulder penetration depth on mechanical properties and failure modes of friction stir spot welds of aluminum 2024-T3 sheets," Journal of Mechanical Science and Technology, vol. 28, no. 12, pp. 4893-4898, 2014. DOI: 10.1007/s12206-014-1108-0.
H. Mehdi, R. S. Mishra, and S. M. Sharif, "Effect of multi-pass friction stir processing and SiC nanoparticles on microstructure and mechanical properties of AA6082-T6," Advances in Industrial and Manufacturing Engineering, vol. 3, pp. 1-14, 2021. DOI: 10.1016/j.aime.2021.100062.
H. Zhang et al., "Effect of tool plunge depth on the microstructure and fracture behavior of refill friction stir spot welded AZ91 magnesium alloy joints," International Journal of Minerals, Metallurgy and Materials, vol. 27, no. 5, pp. 699-709, 2021. DOI: 10.1007/s12613-020-2044-x.
P. L. Threadgill, "Friction stir welds in aluminum alloys–preliminary microstructural assessment," TWI Bulletin, Mar./Apr. 2017.
Grag and A. Bhattachaty, "On lap shear strength of friction stir spot welded AA6061 alloy," Procedia Materials Science, vol. 10, pp. 203-215, 2017. DOI: 10.1016/j.jmapro.2017.02.019.
V. V. Patel et al., "Effect of tool rotation speed on friction stir spot welded AA5052-H32 and AA6082-T6 dissimilar aluminum alloys," Metallography, Microstructure, and Analysis, vol. 5, no. 2, pp. 142-148, 2016. DOI: 10.1007/s13632-016-0264-2.
M. Li, C. Zhang, D. Wang, L. Zhou, D. Wellmann, and Y. Tian, "Friction stir spot welding of aluminum and copper: a review," Materials, vol. 13, no. 1, p. 156, 2020. DOI: 10.3390/ma13010156.
T. Ramkumar et al., "Influence of rotation speeds on microstructure and mechanical properties of welded joints of friction stir welded AA2014-T6/AA6061-T6 alloys," Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, vol. 236, no. 8, pp. 9781-9791, 2022. DOI: 10.1177/09544089231188713.
E. T. Akinlabi, A. S. Osinubi, N. Madushele, S. A. Akinlabi, and O. M. Ikumapayi, "Data on micro hardness and structural analysis of friction stir spot welded lap joints of AA5083-H116," Data in Brief, vol. 30, p. 106585, 2020. DOI: 10.1016/j.dib.2020.106585.
S. Venukumar, B. Baby, S. Muthukumaran, and S. V. Kailas, "Microstructural and Mechanical Properties of Walking Friction Stir Spot Welded AA 6061-T6 Sheets," Procedia Materials Science, vol. 5, pp. 656-665, 2014. DOI: 10.1016/j.mspro.2014.07.081.
V. V. Patel, D. J. Sejani, N. J. Patel, J. J. Vora, B. J. Gandhi, N. R. Padodara, and C. D. Vamja, "Effect of tool rotation speed on friction stir spot welded AA5052-H32 and AA6082-T6 dissimilar aluminum alloys," Metallography, Microstructure, and Analysis, vol. 5, no. 2, pp. 142-148, 2016.
ASTM-E8, Standard Mechanical testing and Evaluation Tensile testing, American Society for Testing and Material, 2000.
ASTM-E290, Standard test method for Bend testing of material for ductility, American Society for Testing and Material, 1998.
ASTM-E3, Standard guide for preparation of metallography specimen, American Society for Testing and Material, 2008.
ASTM-E384, Standard test method for micro-hardness of materials, American Society for Testing and Material, 2008.
M. Bilici and F. Hunt, "The optimization of welding parameters for friction spot welding of high density polyethylene sheets," Materials and Design, vol. 32, no. 7, pp. 4074-4079, 2011. DOI: 10.1016/j.matdes.2011.03.014.
Y. Tozaki, Y. Uematsu, and K. Tokaji, "Effect of tool geometry on microstructure and static strength in friction stir spot welded aluminum alloys," International Journal of Machine Tools and Manufacture, vol. 47, no. 15, pp. 2230-2236, 2007. DOI: 10.1016/j.ijmachtools.2007.07.005.
V. X. Tran, J. Pan, and T. Pan, "Effects of processing time on strengths and failure modes of dissimilar spot friction welds between aluminum 5754-O and 7075-T6 sheets," Journal of Materials Processing Technology, vol. 209, no. 8, pp. 3724-3739, 2009. DOI: 10.1016/j.jmatprotec.2008.08.028.
Z. Zhang, X. Yang, J. Zhang, G. Zhou, X. Xu, and B. Zou, "Effect of welding parameters on microstructure and mechanical properties of friction stir spot welded 5052 aluminum alloy," Materials and Design, vol. 32, no. 8, pp. 4461-4470, 2011. DOI: 10.1016/j.matdes.2011.03.058.
P. Prangnell and D. Baklavas, "Novel Approaches to Friction Spot Welding Thin Aluminum Automotive Sheet," Materials Science Forum, vol. 638-642, pp. 1237-1242, 2010. DOI: 10.4028/www.scientific.net/MSF.638-642.123
