Abstract
The superplastic behavior of thermomechanically treated P/M 7091 aluminum alloy was assessed in the temperature range of 573 to 773 K. The thermomechanical treatment (TMT) comprised of three steps of solution treatment, overaging, and warm rolling. There are large η-phase (MgZn2) precipitate particles of average size of 1.30 μm in the overaged condition. The warm-rolled alloy undergoes continuous recrystallization at the test temperatures of 573 and 623 K, exhibiting a maximum tensile elongation of 450 pct at 573 K and a strain rate of 8 × 10−5 s−1. The precipitate particles play a major role in the process of continuous recrystallization. For a given volume fraction of precipitate particles and constant amount of warm rolling (in the course of TMT), an optimum precipitate particle size is expected to maximize the rate of continuous recrystallization and render the finest recrystallized grain size. The warm-rolled alloy undergoes static recrystallization at temperatures above 673 K. The grain growth accompanying the deformation at these test temperatures limits the tensile ductility to a lower value. Irrespective of the test temperature and strain rate, the specimens undergo extensive cavitation when deformed at elevated temperatures.
Similar content being viewed by others
References
G.W. Stacher and D.E. Weisert: Concurrent Superplastic Forming-Diffusion Bonding of BI Components, Advanced Fabrication Processes, AGARD Conference No. 256, NATO 1979.
S.J. Swadling: Fabrication of Titanium at High Temperatures, AGARD Conference No. 256, NATO 1979.
R. Sawle:Proc. Symp. on Superplastic Forming of Structural Alloys, San Diego, CA, N.E. Paton and C.H. Hamilton, eds., TMS-AIME, Warrendale, PA, 1982, p. 307.
J. Waldman, H. Sulinski, and H. Markus:Metall. Trans. A, 1974, vol. 5A, pp. 573–84.
J. Waldman, H. Sulinski, and H. Markus: U.S. Patent 3,847,681, No. 12, 1974.
J. Waldman, H. Sulinski, and H. Markus:Proc. of Aluminium Alloys in the Aircraft Industry, Turia, Italy, Oct. 1976, Technicopy Ltd., Gloucestershire, England, p. 105.
E. DiRusso, M. Conserva, M. Buratti, and I. Gatto:Mater. Sci. Eng., 1974, vol. 14, p. 23.
J.A. Wert, N.E. Paton, C.H. Hamilton, and M.W. Mahoney:Metall. Trans. A, 1981, vol. 12A, pp. 1267–76.
N.E. Paton, C.H. Hamilton, J.A. Wert, and M.W. Mahoney:J. Met., 1982, vol. 34, p. 21.
J.A. Wert:Superplastic Forming of Structural Alloys, N.E. Paton and C.H. Hamilton, eds., TMS-AIME, Warrendale, PA, 1982, p. 69.
B.M. Watts, M.J. Stowell, B.L. Baikie, and D.G.E. Owen:Met. Sci., 1976, vol. 10, p. 189.
B.M. Watts, M.J. Stowell, B.L. Baikie, and D.G.E. Owen:Met. Sci., 1976, vol. 10, p. 198.
H.N. Azari, G.S. Murty, and G.S. Upadhyaya:Mater. Sci. Technol., 1993, vol. 9, p. 686.
O.D. Sherby and J. Wadsworth:Prog. Mater. Sci., 1989, vol. 33, p. 169.
H.N. Azari, G.S. Murty, and G.S. Upadhyaya:Berg-Hüttenmaenn. Monatsh., 1993, vol. 138 (9).
H.N. Azari, G.S. Murty, and G.S. Upadhyaya:Pract. Metallogr., 1993, vol. 30 (4), p. 186.
H. Alborn, E. Hornbogen, and U. Koster:J. Mater. Sci., 1969, vol. 4, p. 94.
R.H. Bricknell and J.W. Edington:Acta Metall., 1979, vol. 27, p. 1303.
E. Nes:Superplastieity, B. Baudelet and M. Surrey, eds., Editions du CNRS, Paris, 1985, p. 7.1.
S.J. Hales and T.R. McNelley:Superplastieity in Aerospace, H.C. Heikkenen and T.R. McNelley, eds., TMS-AIME, Warrendale, PA, 1988, p. 61.
R. Grimes, M.J. Stowell, and B.M. Watts:Met. Technol., 1976, vol. 3, p. 154.
D.J. Lloyd and D.M. Moore:Superplastic Forming of Structural Alloy, N.E. Paton and C.H. Hamilton, eds., TMS-AIME, Warrendale, PA, 1982, p. 147.
J. Wadsworth:Superplastic Forming, ASM, Metals Park, OH, 1985, p. 43.
W.S. Miller and J. White:Superplastieity in Aerospace, H.C. Heikkenen and T.R. McNelley, eds., TMS-AIME, Warrendale, PA, 1988, p. 211.
R.H. Bricknell and J.W. Edington:Metall. Trans. A, 1979, vol. 10A, pp. 1257–63.
E. Nes:J. Mater. Sci. Lett., 1978, vol. 13, p. 2052.
E. Nes:Metal Sci., 1979, vol. 13, p. 211.
T.R. McNelley, E.-W. Lee, and M.E. Mills:Metall. Trans. A, 1986, vol. 17A, pp. 1035–41.
E.-W. Lee, T.R. McNelley, and A.F. Stengel:Metall. Trans. A, 1986, vol. 17A, pp. 1043–50.
T.R. McNelley, W. Lee, and A. Garg:Aluminum Alloys-Physical and Mechanical Properties, E.A. Starke and T.H. Sanders, eds., Engineering Materials Advisory Services Ltd., West Midlands, United Kingdom, 1986, p. 1269.
E.-W. Lee and T.R. McNelley:Mater. Sci. Eng., 1987, vol. 93, p. 45.
E.-W. Lee and T.R. McNelley:Mater. Sci. Eng., 1987, vol. 96, p. 253.
S.J. Hales and T.R. McNelley:Acta Metall., 1988, vol. 36, p. 1229.
B. Bay and N. Hansen:Metall. Trans. A, 1979, vol. 10A, p. 279–88.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Azari, H.N., Murty, G.S. & Upadhyaya, G.S. Superplastic behavior of thermomechanically treated P/M 7091 aluminum alloy. Metall Mater Trans A 25, 2153–2160 (1994). https://doi.org/10.1007/BF02652316
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02652316