Experimental and numerical investigations of bonding interface behavior in stationary shoulder friction stir lap welding

doi:10.1016/j.jmst.2018.09.028

Abstract

Abstract:

Stationary shoulder friction stir lap welding (SSFSLW) was employed to weld 2024 aluminum alloy. A coupled Eulerian-Lagrangian (CEL) model was developed to investigate the lap interface behavior during SSFSLW. Numerical results of material movement and equivalent plastic strain were in good agreement with the experimental work. With increasing welding speed, the distances from the hook tip to the top surface of the upper workpiece on the retreating side (RS) and the advancing side (AS) increase, while the distance between two wave-shaped alclads decreases. A symmetric interface bending is observed on the AS and the RS during plunging, while the interface bending on the AS is bigger than that on the RS during welding. The peak temperature of the interface on the AS is higher than that on the RS. The equivalent plastic strain gradually increases as the distance to the weld center decreases, and its peak value is obtained near the bottom of the weld.

Key words: Stationary shoulder friction stir lap welding, Coupled Eulerian-Lagrangian, Temperature field, Material distribution, Equivalent plastic strain

Q. Wen, W.Y. Li, W.B. Wang, F.F. Wang, Y.J. Gao, V. Patel. Experimental and numerical investigations of bonding interface behavior in stationary shoulder friction stir lap welding[J]. J. Mater. Sci. Technol., 2019, 35(1): 192-200.

Figures/Tables 19

Fig. 1. Schematic of SSFSLW process.

Fig. 2. (a) Geometry and material assignment of numerical model and (b) mesh generation.

Fig. 3. Temperature-dependent material properties of 2024 aluminum alloy.

Table 1 Johnson-Cook plasticity model constants for 2024 aluminum alloy [24].

A (MPa)	B (MPa)	C	n	m
345	462	0.001	0.25	2.75

Fig. 4. Boundary conditions on workpiece zero speed in X axis (a), Y axis (b) and Z axis (c) (The red zones represent velocity boundary).

Fig. 5. Joint surface appearance of FSW (a) and SSFSLW (b).

Fig. 6. Cross-sections of joints at different welding speeds: (a) 100?mm/min; (b) 150?mm/min; (c) 200?mm/min.

Fig. 7. Hook defects on AS of SSFSLW joints at different welding speeds: (a) 100?mm/min; (b) 150?mm/min; (c) 200?mm/min.

Fig. 8. Hook defects on RS of SSFSLW joints at different welding speeds: (a) 100?mm/min; (b) 150?mm/min; (c) 200?mm/min.

Fig. 9. Lap shear failure load of joints using different welding speeds.

Fig. 10. Disperse alclad in SSFSLW joints at different welding speeds: (a) 100?mm/min; (b) 150?mm/min; (c) 200?mm/min.

Fig. 11. Microstructures of joint with welding speed of 100?mm/min: (a) BM; (b) SZ; (c) TMAZ; (d) HAZ.

Fig. 12. Measured D1 and D2 for different welding speeds.

Fig. 13. Measured D3 for different welding speeds.

Fig. 14. Calculated material distribution at welding speed of 200?mm/min during (a, b) plunging state for 10?s (a), 20?s (b) and welding state for 15?s (c) and 80?s (d).

Fig. 16 shows the thermal cycles of two interface points (points 1 and 2 in Fig. 14), which rises slowly during plunging and rapidly during welding. With increasing welding speed, the peak temperature of the point decreases, which has been observed previously [30]. Compared to point 2, the peak temperature of point 1 is higher for all welding parameters, which is consistent with the study of Commin et al. [31], who observed that the temperature distribution on the AS was higher than that on the RS due to the difference in plastic deformation. As a whole, the extent of plasticity is closely associated with temperature [32], so excellent material flow occurs on the AS. In this case, severe interface bending develops on the AS during the tool rotation, which is also verified by the cross-section of the joint (Fig. 6, Fig. 14).

Fig. 16. Calculated temperature history of interface characteristic point.

Fig. 17. The equivalent plastic strain distributions on joint surface (a) and cross-sections at welding speeds of 100?mm/min (b), 150?mm/min (c) and 200?mm/min (d).

Fig. 18. The equivalent plastic strain curves of bonding interfaces at different welding speeds.

References

[1]	Q. Chu, W.Y. Li, X.W. Yang, J.J. Shen, A. Vairis, W.Y. Feng, W.B. Wang, J. Mater.Sci.Technol. 34(2018) 1739-1746.
[2]	J. Zhang, X.S. Feng, J.S. Gao, H. Huang, Z.Q. Ma, L.J. Guo, J. Mater. Sci.Technol.34(2018) 219-227.
[3]	C.M. Chen, R. Kovacevic, Int. J. Mach. Tools Manuf. 43(2003)1319-1326.
[4]	P.L. Niu, W.Y. Li, Z.H. Zhang, X.W. Yang, J. Mater. Sci.Technol. 33(2017)987-990.
[5]	X.Q. Jiang, B.P. Wynne, J. Martin, J. Mater. Sci.Technol. 34(2018)198-208.
[6]	S.D. Ji, X.C. Meng, L. Ma, H. Lu, S.S. Gao, Mater. Des. 68(2015) 72-79.
[7]	T.J. Yoon, B.H. Jung, C.Y. Kang, Mater. Des. 83(2015) 377-386.
[8]	Z.W. Li, Y.M. Yue, S.D. Ji, P. Chai, Z.L. Zhou, Mater. Des. 90(2016) 238-247.
[9]	S. Babu, G.D.JanakiRam, P.V. Venkitakrishnan, G. MadhusudhanReddy, K.PrasadRao, J. Mater. Sci. Technol. 28(2012) 414-426.
[10]	V. Soundararajan, E. Yarrapareddy, R. Kovacevic, J. Mater. Eng.Perform. 16(2007) 477-484.
[11]	J. Mohammadi, Y. Behnamian, A. Mostafaei, A.P. Gerlich, Mater. Des. 75(2015)95-112.
[12]	Y.M. Yue, Z.L. Zhou, S.D. Ji, L.G. Zhang, Z.W. Li, Int. J. Adv. Manuf. Technol. 25(2016) 1-7.
[13]	H.J. Liu, Y.Q. Zhao, Y.Y. Hu, S.X. Chen, Z. Lin, Int. J. Adv. Manuf. Technol. 78(2015) 1415-1425.
[14]	P.C. Lin, J. Pan, T. Pan, Int. J. Fatigue30 (2008) 74-105.
[15]	H. Badarinarayan, Q. Yang, S. Zhu, Int. J. Mach. Tools Manuf. 49(2009)142-148.
[16]	E. Salari, M. Jahazi, A. Khodabandeh, H. Ghasemi-Nanesa, Mater. Des. 58(2014) 381-389.
[17]	Y.M. Yue, Z.L. Zhou, S.D. Ji, J. Zhang, Z.W. Li, Int. J. Adv. Manuf. Technol. 89(2017) 1691-1698.
[18]	Y.H. Yin, N. Sun, T.H. North, S.S. Hu, J. Mater. Process.Technol. 210(2010)2062-2070.
[19]	L. Dubourg, A. Merati, M. Jahazi, Mater. Des. 31(2010) 3324-3330.
[20]	Q. Yang, X. Li, K. Chen, Y.J. Shi, Mater. Sci. Eng. A 528 (2011) 2463-2478.
[21]	W.H. Deng, P. Wei, L. Xing, W.P. Xu, Thermal Process. 40(2011) 119-122.
[22]	V. Shokri, A. Sadeghi, M.H. Sadeghi, J. Manuf. Process. 31(2018) 46-55.
[23]	F. Al-Badour, N. Merah, A. Shuaib, A. Bazoune, J. Mater. Process.Technol. 213(2013) 1433-1439.
[24]	Z.L. Zhang, J. Shenyang Aerosp.Univ. 31(2014) 47-50.
[25]	F. Al-Badour, N. Merah, A. Shuaib, A. Bazoune, Int. J. Adv. Manuf. Technol. 72(2014) 607-617.
[26]	J.Y. Cao, M. Wang, L. Kong, Y.H. Yin, L.J. Guo, Int. J. Adv. Manuf. Technol. 89(2017) 2129-2139.
[27]	D.X. Li, X.Q. Yang, L. Cui, F.Z. He, H. Shen, Mater. Des. 64(2014) 251-260.
[28]	S. Lathabai, M.J. Painter, G.M.D.Cantin, V.K. Tyagi, Scr. Mater. 55(2006)899-902.
[29]	M.K. Yadava, R.S. Mishra, Y.L. Chen, B. Carlson, G.J. Grant, Sci. Technol. Weld.Join. 15(2010) 70-75.
[30]	H. Fujii, L. Cui, N. Tsuji, M. Maeda, K. Nakata, K. Nogi, Mater. Sci. Eng. A 429(2006) 50-57.
[31]	L. Commin, M. Dumont, J.E. Masse, L. Barrallier, Acta Mater. 57(2009)326-334.
[32]	T.L. Brown, C. Saldana, T.G. Murthy, J.B. Mann, Y. Guo, L.F. Allard, A.H. King,W.D. Compton, K.P. Trumble, S. Chandrasekar, Acta Mater. 57(2009)5491-5500.