Abstract
The precipitation sequence in friction stir weld of 6063 aluminum during postweld aging, associated with Vickers hardness profiles, has been examined by transmission electron microscopy. Friction stir welding produces a softened region in the weld, which is characterized by dissolution and growth of the precipitates. The precipitate-dissolved region contains a minimum hardness region in the aswelded condition. In the precipitate-dissolved region, postweld aging markedly increases the density of strengthening precipitates and leads to a large increase in hardness. On the other hand, aging forms few new precipitates in the precipitate-coarsened region, which shows a slight increase in hardness. The postweld aging at 443 K for 43.2 ks (12 hours) gives greater hardness in the overall weld than in the as-received base material and shifts the minimum hardness from the as-welded minimum hardness region to the precipitate-coarsened region. These hardness changes are consistent with the subsequent precipitation behavior during postweld aging. The postweld solution heat treatment (SHT) and aging achieve a high density of strengthening precipitates and bring a high hardness homogeneously in the overall weld.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
C.E. Cross and G.R. Edwards: in Treatise on Materials Science and Technology, vol. 31, Aluminum Alloys—Contemporary Research and Applications, A.K. Vasudevam and R.D. Doherty, eds., Academic Press New York, NY, 1989, pp. 171–87.
M.B. Ellis and M. Strangwood: Mater. Sci. Technol., 1996, vol. 12, pp. 970–77.
L.A. Guitterez, G. Neye, and E. Zschech: Weld. J., 1996, vol. 75, pp. 115s-121s.
J. Hagstrom and R. Sandstrom: Sci. Technol. Weld. Join., 1997, vol. 2, pp. 199–208.
A.J. Sunwoo and J.W. Morris, Jr.: Weld. J., 1989, vol. 68, pp. 262s-268s.
H. Kokawa, M. Saotome, and T. Kuwana: Proc. 6th Int. Symp. of JWS, JWS, Nagoya, Japan, 1996, pp. 683–88.
C.J. Dawes: Weld. Met. Fabrication, 1995, vol. 63, pp. 13–16.
W.M. Thomas and E.D. Nicholas: Mater. Des., 1997, vol. 18 (4–6), pp. 269–73.
C.G. Rhodes, M.W. Mahoney, W.H. Bingel, R.A. Spurling, and C.C. Bampton: Scripta Mater., 1997, vol. 36, pp. 69–75.
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.
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., 1998, vol. 33, pp. 1243–51.
Y.S. Sato, H. Kokawa, M. Enomoto, and S. Jogan: Metall. Mater. Trans. A, 1999, vol. 30A, pp. 2429–37.
L.E. Murr, G. Liu, and J.C. McClure: J. Mater. Sci. Lett., 1997, vol. 16, pp. 1801–03.
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.
D. Marchive and R. Deschamps: Aluminum, 1979, vol. 55, p. 37.
T. Sheppard: Mater. Sci. Technol., 1998, vol. 4, pp. 635–43.
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.
K. Matsuda, H. Gamada, K. Fujii, Y. Uetani, T. Sato, A. Kamio, and S. Ikeno: Metall. Mater. Trans. A, 1998, vol. 29A, pp. 1161–67.
G.A. Edwards, K. Stiller, and G.L. Dunlop: Appl. Surf. Sci., 1994, vols., 76–77, pp. 219–25.
K. Matsuda, S. Ikeno, and S. Tada: J. Jpn Inst. Met., 1993, vol. 57, pp. 1107–13.
R.J. Livak: Metall. Trans. A, 1982, vol. 13A, pp. 1318–21.
N. Maruyama, R. Uemori, N. Hashimoto, M. Saga, and M. Kikuchi: Scripta Mater., 1997, vol. 36, pp. 89–93.
J.P. Lynch, L.M. Brown, and M.H. Jacobs: Acta Metall., 1982, vol. 30, pp. 1389–95.
H. Yoshida, S. Hirano, and H. Uchida: J. Light Met. Weld. Constr., 1995, vol. 33, pp. 175–83.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sato, Y.S., Kokawa, H., Enomoto, M. et al. Precipitation sequence in friction stir weld of 6063 aluminum during aging. Metall Mater Trans A 30, 3125–3130 (1999). https://doi.org/10.1007/s11661-999-0223-5
Received:
Issue Date:
DOI: https://doi.org/10.1007/s11661-999-0223-5