Impact of Friction Stir Welding (FSW) Process Parameters on Thermal Modeling and Heat Generation of Aluminum Alloy Joints

doi:10.1007/s40195-016-0466-2

Abstract

Abstract:

Friction stir welding (FSW) is a solid-state joining process, where joint properties largely depend on the amount of heat generation during the welding process. The objective of this paper was to develop a numerical thermomechanical model for FSW of aluminum-copper alloy AA2219 and analyze heat generation during the welding process. The thermomechanical model has been developed utilizing ANSYS^? APDL. The model was verified by comparing simulated temperature profile of three different weld schedules (i.e., different combinations of weld parameters in real weld situations) from simulation with experimental results. Furthermore, the verified model was used to analyze the effect of different weld parameters on heat generation. Among all the weld parameters, the effect of rotational speed on heat generation is the highest.

Key words: Friction stir welding, Frictional dissipation energy, Temperature distribution, Friction modeling, Aluminum alloy

Saad B. Aziz,Mohammad W. Dewan,Daniel J. Huggett,Muhammad A. Wahab,Ayman M. Okeil,T. Warren Liao. Impact of Friction Stir Welding (FSW) Process Parameters on Thermal Modeling and Heat Generation of Aluminum Alloy Joints[J]. Acta Metallurgica Sinica (English Letters), 2016, 29(9): 869-883.

Figures/Tables 37

Fig. 1 Schematic of friction stir welding (FSW) process

Fig. 2 Experimental setup and process parameter of FSW (Fz = plunge force, ω = rotational speed, V = travel speed)

Table 1 Chemical composition of the workpiece (AA2219)

Si	Fe	Cu	Mn	Mg	V	Zn	Ti	Zr
0.20	0.30	6.8	0.40	0.02	0.15	0.10	0.10	0.25

Fig. 3 Meshes and thermal boundary conditions of the finite element model

Fig. 4 Modified Coulomb’s law depicting sliding and sticking conditions

Fig. 5 Mechanical boundary conditions of the plate

Fig. 6 Layouts of the thermocouples (embedded in the surface) and thermographer (all dimensions are in millimeter)

Fig. 7 Solid226 elements [27]

Table 3 Temperature-dependent friction coefficient used in the model

Temperature (°C)	Friction coefficient
25	0.4
100	0.4
200	0.4
300	0.35
400	0.25
420	0.25
543	0.01

Fig. 8 Flowchart for choice of friction coefficient

Fig. 9 Contact pair between tool and workpiece and between two plates

Fig. 10 Young’s modulus of aluminum as a function of temperature [34]

Fig. 11 Thermal conductivity of AA2219 as a function of temperature [35]

Fig. 12 Specific heat capacity of AA2219 as a function of temperature [35]

Table 4 Material properties used in the model [36]

Density of workpiece, \({ \rho }\)(kg/ \({\text{m}}^{3} )\)	Density of tool, \({ \rho }_{{\mathbf{t}}}\)(kg/ \({\text{m}}^{3} )\)	Thermal conductivity of the tool, \({k}_{{\mathbf{t}}}\)(W/m2 °C)	Specific capacity of tool, \({c}_{{\mathbf{t}}}\) (J/kg/°C)	Melting temperature of workpiece (°C)
2840	7800	24.4	460	543

Fig. 13 True stress-strain diagram of the aluminum [30, 37]

Fig. 14 Temperature-dependent yield stress of aluminum at \(\dot{\varepsilon }\) = 1 s-1 [30, 37]

Table 5 Different weld schedule for temperature verification

Rotational speed, \({ \omega }\) (rpm)	Travel speed, V (mm/s)	Plunge force,\({ F}_{{{Z }}}\) (kN)
350	1.27	12.455
350	1.27	15.568
350	1.27	21.351

Fig. 15 Comparison between temperature histories of thermocouples and FEA results at y = 42.36 mm, z = 26 mm location (V = 1.27 mm/s; ω = 350 rpm; Fz = 12.455 kN)

Fig. 16 Comparison between temperature histories of thermocouples and FEA results at y = 42.36 mm, z = 26 mm location (V = 1.27 mm/s; \(\omega =\) 350 rpm; Fz = 15.568 kN)

Fig. 17 Comparison between temperature histories of thermocouples and FEA results at y = 42.36 mm, z = 26 mm location (V = 1.27 mm/s; ω = 350 rpm; Fz = 21.351 kN)

Fig. 18 Temperature field from simulation (V = 1.27 mm/s; ω = 350 rpm; Fz = 15.568 N)

Fig. 19 Temperature variation from simulation along transverse direction (V = 1.27 mm/s; \(\omega =\) 350 rpm; Fz = 15.568 kN)

Fig. 20 Comparison of temperature variations between experimental and simulation data along transverse direction (V = 1.27 mm/s; \(\omega =\) 350 rpm; Fz = 12.455 kN)

Fig. 21 Comparison of temperature variations between experimental and simulation data along transverse direction (V = 1.27 mm/s; ω = 350 rpm; Fz = 15.568 kN)

Fig. 22 Comparison of temperature variation between experimental and simulation data along transverse direction (V = 1.27 mm/s; \(\omega =\) 350 rpm; Fz = 21.351 kN)

Table 6 Error analysis for Fz = 12.455 kN, ω = 350 rpm, V = 1.27 mm/s weld schedule

Distance (mm)	Temperature from FEA analysis (°C)	Temperature from experiment (°C)	Absolute error (%)
0	422	418	0.96
15	354	342	3.51
26	262	248	5.64
32	237	225	5.30
39	220	212	3.77
47	213	208	2.40
		Average error	3.60

Table 7 Error analysis for Fz = 15.568 kN, ω = 350 rpm, V = 1.27 mm/s weld schedule

Distance (mm)	Temperature from FEA analysis (°C)	Temperature from experiment (°C)	Absolute error (%)
0	431.0	440	2.04
15	362.3	360	0.64
26	288.9	280	3.18
32	255.3	252	1.31
39	220.8	230	4.00
47	214.0	216	0.39
		Average error	2.02

Table 8 Error analysis for Fz = 21.351 kN, ω = 350 rpm, V = 1.27 mm/s weld schedule

Distance (mm)	Temperature from FEA analysis (°C)	Temperature from experiment (°C)	Absolute error (%)
0	458.66	462	0.72
15	398.56	403	1.10
26	298.56	304	1.79
32	260.4	265	1.73
39	244.65	252	2.91
47	232.04	238	2.50
		Average error	1.79

Table 9 Friction and plastic dissipation energy for weld schedule plunge force 21.351 kN, rotation rate 350 rpm, and traverse speed 1.27 mm/s

Rotational speed, \({\omega }\)(rpm)	Traverse speed, V (mm/s)	Plunge force, \({ F}_{{Z}}\) (kN)	Frictional energy (J)	Plastic energy (J)	Total energy (J)
350	1.27	21.351	1.35 × 10⁶	1.25 × 10³	1.35125 × 10⁶

Fig. 23 Frictional dissipation energy variation with plunge force (ω = 350 rpm, v = 1.27 mm/s)

Table 10 Summary of friction dissipation energies for various plunge forces

Rotational speed, \({\omega}\) (rpm)	Traverse speed, V (mm/s)	Plunge force, \({ F}_{{Z}}\), (kN)	Frictional energy (J)	Frictional energy percentage increasea
350	1.27	12.455	1.04 × 10⁶	22.96%
350	1.27	15.568	1.06 × 10⁶	21.48%
350	1.27	21.351	1.35 × 10⁶	Base1

Fig. 24 Frictional dissipation energy variation with rotational speed (v = 1.27 mm/s, Fz = 26.68 kN)

Table 11 Summary of friction dissipation energies for various rotational speeds

Rotational speed, \({\omega}\), (rpm)	Traverse speed, V (mm/s)	Plunge force, \({F}_{{Z}}\), (kN)	Total frictional energy (J)	Frictional energy percentage increasea
200	2.539	26.68	3.09 × 10⁵	80.06%
300	2.539	26.68	1.05 × 10⁶	32.25%
450	2.539	26.68	1.55 × 10⁶	Base2

Fig. 25 Frictional dissipation energy variation with welding speed (Fz = 26.68 kN, \(\omega\) = 300 rpm)

Table 12 Summary of total friction and plastic dissipation energies for various travel speed

Rotational speed, \({\omega}\), (rpm)	Travel speed, V (mm/s)	Plunge force, \({F}_{{Z}}\), (kN)	Total frictional energy (J)	Frictional energy percentage increasea
300	3.386	26.68	1.05 × 10⁶	5.40%
300	2.539	26.68	1.06 × 10⁶	4.50%
300	1.693	26.68	1.11 × 10⁶	Base3

References

[1]	W.M. Thomas, E.D. Nicholas, J.C. Needham, M.G. Murch, P. Templesmith, C.J. Dawes, Dec 1991
[2]	Z. Feng, X.L. Wang, S.A. David, P.S. Sklad, Sci. Technol. Weld. Join. 12, 348(2007)
[3]	X.K. Zhu, Y.J. Chao, J. Mater. Process. Technol. 146, 263(2004)
[4]	M.Z.H. Sci. Technol. Weld. Join. 8, 165(2003)
[5]	P. Prasanna, B.S. Rao, G.K.M. Int. J. Adv. Manuf. Technol. 51, 925(2010)
[6]	R. Nandan, G.G. Roy, T. Debroy, Metall. Mater. Trans. A 37, 1247 (2006)
[7]	P.A. Colegrove, H.R. Shercliff, Sci. Technol. Weld. Join. 11, 429(2006)
[8]	P. Ulysse, Int. J. Mach. Tools Manuf. 42, 1549(2002)
[9]	E. Ranjbarnodeh, S. Hanke, S. Weiss, A. Fischer, Int. J. Miner. Metall. Mater. 19, 923(2012)
[10]	Y.H. Yau, A. Hussain, R.K. Lalwani, H.K. Chan, N. Hakimi, Int. J. Miner. Metall. Mater. 20, 779(2013)
[11]	S.D. Jai, Y.Y. Jin, Y.M. Yue, S.S. Gao, Y.X. Huang, J. Mater. Sci. Technol. 29, 955(2013)
[12]	H.B. Schmidt, J.H. Hattel, Scr. Mater. 58, 332(2008)
[13]	H. Schmidt, J. Hattel, J. Wert, Model. Simul. Mater. Sci. Eng. 12, 143(2004)
[14]	M. Song, R. Kovacevic, Int. J. Mach. Tools Manuf. 43, 605(2003)
[15]	C. Chen, R. Kovacevic, Proc. Inst. Mech. Eng. Part C J. Eng. Mech. Eng. Sci. 218, 509(2004)
[16]	X.X. Zhang, B.L. Xiao, Z.Y. Ma, Metall. Mater. Trans. A 42, 3218 (2011)
[17]	X.X. Zhang, B.L. Xiao, Z.Y. Ma, Metall. Mater. Trans. A 42, 3229 (2011)
[18]	G. Buffa, J. Hua, R. Shivpuri, L. Fratini, Mater. Sci. Eng. A 419, 389 (2006)
[19]	Z. Zhang, H.W. Zhang, Sci. Technol. Weld. Join. 12, 226(2007)
[20]	Z. Zhang, H.W. Zhang, Mater. Des. 30, 900(2009)
[21]	H.W. Zhang, Z. Zhang, J.T. Chen, J. Mater. Process. Technol. 183, 62(2007)
[22]	D. Wang, B.L. Xiao, D.R. Ni, Z.Y. Ma, Acta Metall. Sin. (Engl. Lett.) 27, 816(2014)
[23]	A.H. Feng, D.L. Chen, Z.Y. Ma, W.Y. Ma, R.J. Song, Acta Metall. Sin. (Engl. Lett.) 27, 723(2014)
[24]	W.F. Xu, J.H. Liu, D.L. Chen, J. Mater. Sci. Technol. 31, 953(2015)
[25]	R.Z. Xu, D.R. Ni, Q. Yang, C.Z. Liu, Z.Y. Ma, J. Mater. Sci. Technol. 32, 76(2016)
[26]	M.W. Dewan, D.J. Hugget, T.W. Liao, M.A. Wahab, A.M. Okeil, Mater. Des. 92, 288(2016)
[27]	Ansys Inc., ANSYS Mechanical APDL Theory Reference, 2013, Accessed on 28 Aug 2015
[28]	A.P. Reynolds, T. Seidel, 9-12 Oct, 2000
[29]	Y.J. Chao, X. Qi, W. Tang, Trans. ASME 125, 138 (2003)
[30]	M. Awang, West Virginia University, 2007
[31]	R.S. Mishra, Z.Y. Ma, Mater. Sci. Eng. R 50, 1 (2005)
[32]	A. Bastier, M.H. Maitournam, K. Dang, F. Roger, Sci. Technol. Weld. Join. 11, 278(2006)
[33]	Ansys Inc., Theory Reference for the Mechanical APDL and Mechanical Applications, 2009, . Accessed on 2 Aug 2015
[34]	R.B. J. Phys. Chem. Solids 48, 603 (1987)
[35]	H.J. Zhang, H.J. Liu, L. Yu, Trans. Nonferrous Met. Soc. China 23, 1114 (2013)
[36]	ASM International Handbook Committee, Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (ASM Handbook, ASM International, Materials park, OH 1990), p. 65
[37]	E. Semb, Norwegian University of Science and Technology, 2013
[38]	X.G.W. J. Mater. Process. Manuf. Sci. 163, 7(1998)