Abstract
Dominant microstructural factors governing the global tensile properties of a friction-stir-welded joint of 6063 aluminum were examined by estimating distribution of local tensile properties corresponding to local microstructure and hardness. Yield and ultimate tensile strengths of the as-welded weld were significantly lower than those of the base material. Postweld aging and postweld solution heat-treatment and aging (SHTA) restored the strengths of the weld to the levels of the base material. Elongation was found to increase with increasing strength. Hardness tests showed that the as-welded weld was soft around the weld center and that the aged weld and the SHTA weld had relatively homogeneous distributions of high hardness. Hardness profiles of the welds were explained by precipitate distributions and precipitation sequences during the postweld heat treatments. The strengths of the welds were related to each minimum hardness value. In a weld having a heterogeneous hardness profile, the fracture occurred in the region with minimum hardness. When a weld had a homogeneous hardness profile, its fracture site depended on both crystallographic-orientation distribution of the matrix grains and strain tensor of the imposed deformation, i.e., it fractured in the region with a minimum average Taylor factor.
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C.J. Dawes: Welding Met. Fabrication, 1995, vol. 63, pp. 13–16.
C.J. Dawes and W.M. Thomas: Weld. J., 1996, vol. 75, pp. 41–45.
E.D. Nicholas: Proc. ICAA-6, Toyohashi, Japan, 1998, The Japan Institute of Light Metals, Tokyo, Japan, vol. 1, pp. 139–51.
C.J. Dawes: Proc. 6th Int. Symp. of JWS, JWS, Nagoya, 1996, pp. 711–17.
M.R. Johnsen: Weld. J., 1999, vol. 78, pp. 35–39.
H. Okamura, K. Aota, and M. Ezumi: J. Jpn Inst. Light Met., 2000, vol. 50, pp. 166–71.
S. Kallee, D. Richardson, and I. Henderson: Schweissen Schneiden (Welding Cutting), 1997, vol. 49, pp. 904–909 (E178–180).
O. Kluken and M. Ranes: Svetsaren, 1995, vol. 3, pp. 13–15.
C.G. Rhodes, M.W. Mahoney, W.H. Bingel, R.A. Spurling, and C.C. Bampton: Scripta Mater., 1997, vol. 36, pp. 69–75.
G. Liu, L.E. Murr, C.-S. Niou, J.C. McClure, and F.R. Vega: Scripta Mater., 1997, vol. 37, pp. 355–61.
L.E. Murr, G. Liu, and J.C. McClure: J. Mater. Sci. Lett., 1997, vol. 16, pp. 1801–03.
L.E. Murr, G. Liu, and J.C. McClure: J. Mater. Sci., 1998, vol. 33, pp. 1243–51.
O.V. Flores, C. Kennedy, L.E. Murr, D. Brown S. Pappu, B.M. Nowak, and J.C. McClure: Scripta Mater., 1998, vol. 38, pp. 703–08.
M.W. Mahoney, C.G. Rhodes, J.G. Flintoff, R.A. Spurling, and W.H. Bingel: Metall. Mater. Trans. A, 1998, vol. 29A, pp. 1955–64.
Y.S. Sato, H. Kokawa, M. Enomoto, and S. Jogan: Metall. Mater. Trans. A, 1999, vol. 30A, pp. 2429–37.
Y.S. Sato, H. Kokawa, M. Enomoto, S. Jogan, and T. Hashimoto: Metall. Mater. Trans. A, 1999, vol. 30A, pp. 3125–30.
Y. Li, L.E. Murr, and J.C. McClure: Mater. Sci. Eng. A, 1999, vol. 271, pp. 213–23.
S. Benavides, Y. Li, L.E. Murr, D. Brown, and J.C. McClure: Scripta Mater., 1999, vol. 41, pp. 809–15.
R.S. Mishra, M.W. Mahoney, S.X. McFadden, N.A. Mara, and A.K. Mukherjee: Scripta Mater., 2000, vol. 42, pp. 168–68.
K.V. Jata, K.K. Sankaran, and J.J. Ruschau: Metall. Mater. Trans. A, 2000, vol. 31A, pp. 2181–92.
K.V. Jata and S.L. Semiatin: Scripta Mater., 2000, vol. 43, pp. 743–49.
O.T. Midling: Proc. ICAA-4, Georgia Institute of Technology, Atlanta, GA, 1994, pp. 451–58.
M.B. Ellis and M. Strangwood: Mater. Sci. Technol., 1996, vol. 12, pp. 970–77.
Y. Li, L.E. Murr, and J.C. McClure: Scripta Mater., 1999, vol. 40, pp. 1041–46.
G.S. Frankel and Z. Xia: Corrosion, 1999, vol. 22, pp. 139–50.
Y.S. Sato, H. Kokawa, K. Ikeda, M. Enomoto, S. Jogan, and T. Hashimoto: Metall. Mater. Trans. A, 2001, vol. 32A, pp. 941–48.
B.L. Adams, S.I. Wright, and K. Kunze: Metall. Trans. A, 1993, vol. 24A, pp. 819–31.
D.J. Dingley and D.P. Field: Mater. Sci. Technol., 1997, vol. 13, pp. 69–78.
K. Colligan: Weld. J., 1999, vol. 78, pp. 229s-237s.
M.F. Ashby and D.R.H. Jones: Engineering Materials I, Pergamon Press, Oxford, United Kingdom, 1980, p. 105.
D.L. Zhang and L. Zheng: Metall. Mater. Trans. A, 1996, vol. 27A, pp. 3983–91.
M.H. Jacobs: Phil. Mag., 1972, vol. 26, pp. 1–13.
H. Westengen and N. Ryum: Z. Metallkd., 1979, vol. 70, pp. 528–35.
I. Dutta and S.M. Allen: J. Mater. Sci. Lett., 1991, vol. 10, pp. 323–26.
D.H. Bratland, Ø. Grong, H. Shercliff, O.R. Myhr, and S. Tjøtta: Acta Mater., 1997, vol. 45, pp. 1–22.
S. Amelinckx and W. Dekeyser: Solid State Phys., 1959, vol. 8, p. 325.
H. Kokawa, T. Watanabe, and S. Karashima: Scripta Metall., 1987, vol. 21, p. 839.
V. Randle and B. Ralph: J. Mater. Sci., 1986, vol. 21, p. 3829.
G.I. Taylor: J. Inst. Met., 1938, vol. 62, pp. 307–24.
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Sato, Y.S., Kokawa, H. Distribution of tensile property and microstructure in friction stir weld of 6063 aluminum. Metall Mater Trans A 32, 3023–3031 (2001). https://doi.org/10.1007/s11661-001-0177-8
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DOI: https://doi.org/10.1007/s11661-001-0177-8