Abstract
Because joining dissimilar metals is often difficult by fusion joining, interest has been growing rapidly in using friction stir welding (FSW), which is considered a revolutionary solid-state welding process, as a new way to join dissimilar metals such as Al alloys to Mg alloys, Cu, and steels. Butt FSW of Al to Mg alloys has been studied frequently recently, but the basic issue of how the welding conditions affect the resultant joint strength still is not well understood. Using the widely used alloys 6061 Al and AZ31 Mg, the current study investigated the effect of the welding conditions, including the positions of Al and Mg with respect to the welding tool, the tool travel speed, and the tool rotation speed on the weld strength. Unlike previous studies, the current study (1) determined the heat input by both torque and temperature measurements during FSW, (2) used color metallography with Al, Mg, Al3Mg2, and Al12Mg17 all shown in different colors to reveal clearly the formation of intermetallic compounds and material flow in the stir zone, which are known to affect the joint strength significantly, and (3) determined the windows for travel and rotation speeds to optimize the joint strength for various material positions. The current study demonstrated clearly that the welding conditions affect the heat input, which in turn affects (1) the formation of intermetallics and even liquid and (2) material flow. Thus, the effect of welding conditions in Al-to-Mg butt FSW on the joint strength now can be explained.
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References
C. Conrardy: 8 th Int. Conf. on Trends in Welding Research, Pine Mountain, GA, 2008.
K. Nakada and M. Ushio: J. Jpn. Weld Soc., 2002, vol. 71, no. 6, pp. 6–9.
W.M. Thomas, E.D. Nicholas, J.C. Needham, M.G. Murch, P. Temple-Smith, and C.J. Dawes: Patent International 9 125 978.8, 1991.
A.A. McLean, G.L.F. Powell, I.H. Brown, and V.M. Linton: STWJ, 2003, vol. 8, no. 6, pp. 462–64.
S. Hirano, K. Okamoto, M. Doi, H. Okamura, M. Inagaki, and Y. Aono: Weld. Int., 2004, vol. 18, no. 9, pp. 702–08.
H. Okamura and K. Aota: Weld. Int., 2004, vol. 18, no. 11, pp. 852–60.
A.C. Somasekharan and L.E. Murr: Mater. Charact., 2004, vol. 52, pp. 49–64.
A.C. Somasekharan and L.E. Murr: J. Mater. Sci., 2006, vol. 41, pp. 5365–70.
Y. Sato, S.H.C. Park, M. Michiuchi, and H. Kokawa: Scripta Mater., 2004, vol. 50, pp. 1233–36.
J. Yan, Z. Xu, Z. Li, L. Li, and S. Yang: Scripta Mater., 2005, vol. 53, pp. 585–89.
R. Zettler, J.F. Dos Santos, A. Blanco, and A. da Silva: Proc. 7 th Int. Conf. on Trends in Welding Research, ASM International, Pine Mountain, GA, 2005, pp. 413–19.
R. Zettler, A.A.M. da Silva, S. Rodrigues, A. Blanco, and J.F. de Santos: Adv. Eng. Mater., 2006, vol. 8, no. 5, pp. 415–21.
Y.J. Kwon, I. Shigematsu, and N. Sato: Mater. Lett., 2008, vol. 62, pp. 3827–29.
A. Kostka, R.S. Coelho, J. dos Santos, and A.R. Pyzalla: Scripta Mater., 2009, in press.
C. Liu, D.L. Chen, S. Bhole, X. Cao, and M. Jahazi: Mater. Charact., 2009, vol. 60, pp. 370–76.
P. Venkateswaran, Z. Xu, X. Li, and A.P. Reynolds: J. Mater. Sci., 2009, vol. 44, pp. 4140–47.
V. Firouzdor and S. Kou: Weld. J., 2009, vol. 88, pp. 213s-24s.
Y.K. Yang, H. Dong, H. Cao, Y.A. Chang, and S. Kou: Weld. J., 2008, vol. 87, pp. 167s-77s.
Y.K. Yang, H. Dong, and S. Kou: Weld. J., 2008, vol. 87, pp. 202s-11s.
G. Cao and S. Kou: Weld. J., 2005, vol. 84, pp. 1s-8s.
S. Kou: Welding Metallurgy, 2nd ed., Wiley, New York, NY, 2003, pp. 303–39.
American Society for Metals: Binary Alloy Phase Diagrams, vol. 1, ASM, Materials Park, OH, 1986, p. 106.
J.J. Pepe and W.F. Savage: Weld. J., 1967, vol. 46, no. 9, pp. 411s-22s.
J.J. Pepe and W.F. Savage: Weld. J., 1970, vol. 49, no. 12, pp. 545s-53s.
J.W. Pew, T.W. Nelson, and C.D. Sorensen: STWJ, 2007, vol. 12, pp. 341–47.
A.P. Gerlich: Ph.D. Dissertation, University of Toronto, Toronto, ON, Canada, 2007.
R. Nandan, G.G. Roy, and T. DebRoy: Metall. Mater. Trans. A, 2006, vol. 37A, pp. 1247–59.
R. Nandan, T. DebRoy, and H.K.D.H. Bhadeshia: Progr. Mater. Sci., 2008, vol. 53, pp. 980–1023.
J.H. Cho, D.E. Boyce, and P.R. Dawson: Mater. Sci. Eng. A, 2005, vol. 398, pp. 146–63.
J.H. Cho, D.E. Boyce, and P.R. Dawson: Mater. Sci. Eng., 2007, vol. 15, pp. 469–86.
L. Commin, M. Dumont, J.-E. Masse, and L. Barrallier: Acta Mater., 2009, vol. 57, pp. 326–34.
V. Firouzdor and S. Kou: Metall. Mater. Trans. A, in press.
Acknowledgments
This work was supported by the Wisconsin Alumni Research Foundation (WARF) of the University of Wisconsin-Madison. The helpful comments and suggestions made by the reviewers of the manuscript are highly appreciated. The authors would like to thank Professor F.E. Pfefferkorn and his graduate student A. Fehrenbacher of the Mechanical Engineering Department for their assistance in the measurements of torque and forces during FSW. They also would like to thank Dr. John H. Fournelle of the Department of Geoscience for his assistance in EPMA and SEM.
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Firouzdor, V., Kou, S. Al-to-Mg Friction Stir Welding: Effect of Material Position, Travel Speed, and Rotation Speed. Metall Mater Trans A 41, 2914–2935 (2010). https://doi.org/10.1007/s11661-010-0340-1
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DOI: https://doi.org/10.1007/s11661-010-0340-1