Numerical Simulation for the Optimization of Polygonal Pin Profiles in Friction Stir Welding of Aluminum

doi:10.1007/s40195-021-01198-1

Abstract

Abstract:

The tool with polygonal pin profile has been widely employed in friction stir welding (FSW) of aluminum, but there is hardly an effective optimization methodology existed as the thermomechanical characteristics affected by pins with various flats number have not been understood comprehensively. Therefore, the present work employs a 3-dimensional computational fluid dynamics (CFD) model to have an integrated observation of the FSW process with the effect of polygonal pin profiles. Both the heat generation modes due to contact friction at the tool-workpiece interface and volumetric viscous dissipation in the vicinity of the tool are considered. The model is utilized to give a quantitative analysis of the heat generation, temperature distribution, plastic material flow and welding loads during the FSW process for various tools with polygonal pin profiles, as well as a variety of shoulder diameters, welding speeds and tool rotation speeds. The calculated results of thermal cycles, tool torques and joint cross sections for some typical polygonal pins and welding parameters are all found to be compared well with the experimental ones, which demonstrates the feasibility and applicability of the present numerical model. Particularly, a methodology is developed for the optimization of the flats number by identifying the torque components in both parallel and vertical direction of the pin-side flat region. The results show that the optimized pin flats number increases with increasing tool rotation speed, while the influence of both welding speed and shoulder diameter can be supposed to be insignificant. Moreover, the dependability of the optimized results is also discussed by considering wear tendency and service life of the pin for multiple welding conditions.

Key words: Friction stir welding, Polygonal pin, Numerical simulation, Optimization design, Aluminum

Hao Su, Chuansong Wu. Numerical Simulation for the Optimization of Polygonal Pin Profiles in Friction Stir Welding of Aluminum[J]. Acta Metallurgica Sinica (English Letters), 2021, 34(8): 1065-1078.

Figures/Tables 13

Fig. 1 Horizontal cross sections of polygonal pin profiles used in the present study

Fig. 2 Calculated heat generation rates of various polygonal pin profiles (shoulder diameter: 15 mm, tool rotation speed: 800 rpm, welding speed: 160 mm/min)

Fig. 3 Calculated frictional heat generation rate at the tool-workpiece interface of various polygonal pin profiles (shoulder diameter: 15 mm, tool rotation speed: 800 rpm, welding speed: 160 mm/min)

Fig. 4 Calculated peak temperature with different polygonal pin profiles and shoulder diameters (tool rotation speed: 800 rpm, welding speed: 160 mm/min)

Fig. 5 Calculated temperature distribution on three horizontal planes of various polygonal pin profiles (shoulder diameter: 15 mm, tool rotation speed: 800 rpm, welding speed: 160 mm/min)

Fig. 6 Comparison of the thermal cycles between predicted and measured results (shoulder diameter: 15 mm, tool rotation speed: 800 rpm, welding speed: 160 mm/min): a T4f, b Conical

Fig. 7 Calculated material flow on three horizontal planes around various polygonal pin profiles (shoulder diameter: 15 mm, tool rotation speed: 800 rpm, welding speed: 160 mm/min)

Fig. 8 Calculated volume of plastic deformation zone with different polygonal pin profiles and shoulder diameters (tool rotation speed: 800 rpm, welding speed: 160 mm/min)

Fig. 9 Comparison of the weld cross section between experimental and calculated results (shoulder diameter: 15 mm, tool rotation speed: 800 rpm, welding speed: 160 mm/min): a T4f, b Conical

Fig. 10 Calculated tool torque for different shoulder diameters and welding parameters (ω/v): a SD: 12 mm, 400/160, b SD: 15 mm, 600/160, c SD: 15 mm, 800/160, d SD: 18 mm, 800/160

Fig. 11 Comparison of the tool torques between measured and calculated results for various polygonal pin profiles, shoulder diameters and welding parameters

Fig. 12 Calculated parallel and vertical torque components on the side surface of polygonal pin for different shoulder diameters and welding parameters (ω/v): a SD: 12 mm, 400/160, b SD: 15 mm, 600/160, c SD: 15 mm, 800/160, d SD: 18 mm, 800/160

Fig. 13 Calculated results of the optimization function for various shoulder diameters and welding parameters (ω/v): a 400/80, b 400/160, c 600/80, d 600/160, e 800/80, f 800/160

References 36

[1]	R.S. Mishra, Z.Y. Ma, Mat. Sci. Eng. R 50, 1(2005)
[2]	Z.Y. Ma, Acta. Metall. Sin-Engl. Lett. 33, 1(2020)
[3]	R. Rai, A. De, H.K.D.H. Bhadeshia, T. DebRoy, Sci. Technol. Weld. Joi. 16, 325(2011) DOI URL
[4]	Y.N. Zhang, X. Cao, S. Larose, P. Wanjara, Can. Metall. Quart. 51, 250(2012) DOI URL
[5]	X.C. Liu, Y.Q. Zhen, Z.K. Shen, H.Y. Chen, W.Y. Li, W. Guo, Z.F. Yue, Chin. J. Mech. Eng. En. 33, 99(2020)
[6]	K. Elangovan, V. Balasubramanian, Mat. Sci. Eng. A 459, 7(2007)
[7]	A. Tongne, C. Desrayaud, M. Jahazi, E. Feulvarch, J. Mater. Process. TechnolTechnol. 239, 284(2017)
[8]	K.K. Mugada, K. Adepu, J. Manuf. Process. 32, 625(2018) DOI URL
[9]	J. Schneider, S. Brooke, A.C. Nunes, Metall. Mater. Trans. B 47, 720(2016)
[10]	V.V. Patel, V. Badheka, A. Kumar, J. Mater. Process. Technol. 240, 68(2017) DOI URL
[11]	C.V. Rao, G.M. Reddy, K.S. Rao, Def. Technol. 11, 197(2015)
[12]	P. Mastanaiah, A. Sharma, G.M. Reddy, J. Mater. Process. Technol. 257, 257(2018) DOI URL
[13]	K. Ramanjaneyulu, G.M. Reddy, A.V. Rao, R. Markandeya, J. Mater. Eng. Perform. 22, 2224(2013) DOI URL
[14]	D. Trimble, G.E. O’Donnell, J. Monaghan, J. Manuf. Process. 17, 141(2015) DOI URL
[15]	V.S. Gadakh, A. Kumar, J.V. Patil, Weld. J. 93, 115(2015)
[16]	M. Mehta, G.M. Reddy, A.V. Rao, A. De, Def. Technol. 11, 229(2015)
[17]	B.M.A. Al Bhadle, R.A.A. Al Azzawi, R. Thornton, K. Beamish, S. Shi, H.B. Dong, Sci. Technol. Weld. Joi. 24, 93(2019) DOI
[18]	S.B. Aziz, M.W. Dewan, D.J. Huggett, M.A. Wahab, A.M. Okeil, T.W. Liao, Acta. Metall. Sin. Engl. Lett. 31, 1(2018)
[19]	S.B. Aziz, M.W. Dewan, D.J. Huggett, M.A. Wahab, A.M. Okeil, T.W. Liao, Acta. Metall. Sin. Engl. Lett. 29, 869(2016)
[20]	P.A. Colegrove, H.R. Shercliff, Technol. Weld. Joi. 9, 352(2004)
[21]	P.A. Colegrove, H.R. Shercliff, J. Mater. Process. Technol. 169, 320(2005) DOI URL
[22]	Z. Sun, C.S. Wu, S. Kumar, J. Manuf. Process. 31, 801(2018) DOI URL
[23]	Z. Sun, C.S. Wu, J. Mater. Process. Technol 275, 116281(2020) DOI URL
[24]	G. Chen G, H. Li H, G. Wang, Z. Guo, S. Zhang, Q. Dai, X. Wang, G. Zhang, Q. Shi, Int. J. Mach. Tool. Manu. 124, 12(2018) DOI URL
[25]	G. Chen, S. Zhang, Y. Zhu, C. Yang, Q. Shi, Acta. Metall. Sin. Engl. Lett. 33, 3(2020)
[26]	H. Su, L. Xue, C. Wu, Int. J. Adv. Manuf. Technol. 108, 721(2020) DOI URL
[27]	H. Su, C.S. Wu, M. Bachmann, M. Rethmeier, Mater. Des. 77, 114(2015) DOI URL
[28]	Y. Zhu, G. Chen, Q. Chen, G. Zhang, Q. Shi, Mater. Des. 108, 400(2016) DOI URL
[29]	M. Mehta, A. De, T. DebRoy, Sci. Technol. Weld. Joi. 19, 534(2014) DOI URL
[30]	H. Wang, P.A. Colegrove, J.F. dos Santos, Comp. Mater. Sci. 71, 101(2013) DOI URL
[31]	M. Mehta, A. Arora, A. De, T. DebRoy, Metall. Mater. Trans. A 42, 2716(2011)
[32]	A. Arora, A. De, T. DebRoy, Scr. Mater. 64, 9(2011) DOI URL
[33]	G. Chen, Q. Ma, S. Zhang, J. Wu, G. Zhang, Q. Shi, J. Mater. Sci. Technol. 34, 128(2018) DOI URL
[34]	J.F. Archard, J. Appl. Phys. 24, 981(1953) DOI URL
[35]	A. Arora, M. Mehta, A. De, T. DebRoy, Int. J. Adv. Manuf. Technol. 61, 911(2012) DOI URL
[36]	P. Sahlot, K. Jha, G.K. Dey, A. Arora, Metall. Mater. Trans. A. 49, 2139(2018) DOI URL