Effects of alloy composition and casting speed on structure formation and hot tearing during direct-chill casting of Al-Cu alloys
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Abstract
Effects of casting speed and alloy composition on structure formation and hot tearing during direct-chill (DC) casting of 200-mm round billets from binary Al-Cu alloys are studied. It is experimentally shown that the grain structure, including the occurrence of coarse grains in the central part of the billet, is strongly affected by the casting speed and alloy composition, while the dendritic arm spacing is mostly dependent on the casting speed. The hot cracking pattern reveals the maximum hot-tearing susceptibility in the range of low-copper alloys (1 to 1.5 pct) and at high casting speeds (180 to 200 mm/min). The clear correlation between the amount of nonequilibrium eutectics (representing the reserve of liquid phase in the last stage of solidification) and hot tearing is demonstrated. A casting speed-copper concentration-hot-tearing susceptibility chart is constructed experimentally for real-scale DC casting. Computed dimensions of the solidification region in the billet are used to explain the experimentally observed structure patterns and hot cracking. Thermomechanical finite-element simulation of the solidifying billet was used as a tool for testing the applicability to DC casting of several hot-tearing criteria based on different principles. The results are compared to the experimentally observed hot tearing. It is noted that hot-tearing criteria that account for the dynamics of the process, e.g., strain rate, actual stress-strain situation, feeding rate, and melt flow, can be successfully used for the qualitative prediction of hot tearing.
Keywords
Material Transaction Mushy Zone Casting Speed High Casting Speed Round BilletPreview
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References
- 1.E.F. Emley: Int. Met. Rev., 1976, vol. 206, pp. 75–115.Google Scholar
- 2.I.I. Novikov: Hot Shortness of Non-Ferrous Metals and Alloys, Nauka, Moscow, 1966.Google Scholar
- 3.T.W. Clyne and G.J. Davies: Proc. Conf. on Solidification and Castings of Metals, The Metals Society, London, 1979, pp. 275–78.Google Scholar
- 4.D.G. Eskin, Suyitno, and L. Katgerman: Progr. Mater. Sci., 2004, vol. 49, pp. 629–711.CrossRefGoogle Scholar
- 5.V.A. Livanov, R.M. Gabidullin, and V.S. Shepilov: DC Casting of Aluminum Alloys, Metallurgiya, Moscow, 1977.Google Scholar
- 6.D.G. Eskin, J. Zuidema, Jr., V.I. Savran, and L. Katgerman: Mater. Sci. Eng. A, 2004, in press.Google Scholar
- 7.H. Nagaumi, K. Aoki, K. Komatsu, and N. Hagizawa: Mater. Sci. Forum, 2000, vols. 331–337, pp. 173–78.Google Scholar
- 8.M. M’Hamdi, R. Kieft, D. Mortensen, A. Mo, and J. Rabenberg: Aluminium, 2002, vol. 78, pp. 847–851.Google Scholar
- 9.K. Buxmann and E. Gold: JOM, 1982, vol. 4, pp. 28–34.Google Scholar
- 10.M.C. Flemings: Solidification Processing, McGraw-Hill, New York, NY, 1974.Google Scholar
- 11.H. Nagaumi: Sci. Technol. Adv. Mater., 2001, vol. 2, pp. 49–57.CrossRefGoogle Scholar
- 12.N.N. Prokhorov: Russian Castings Production, 1962, vol. 2, pp. 172–75.Google Scholar
- 13.I.I. Novikov and O.E. Grushko: Mater. Sci. Technol., 1995, vol. 11, pp. 926–32.Google Scholar
- 14.U. Feurer: Quality Control of Engineering Alloys and the Role of Metals Science, Delft University of Technology, Delft, The Netherlands, 1977, pp. 131–45.Google Scholar
- 15.L. Katgerman: JOM, 1982, vol. 34 (2), pp. 46–49.Google Scholar
- 16.B. Magnin, L. Katgerman, and B. Hannart: in Modeling of Casting Welding and Advanced Solidification Processes VII, M. Cross and J. Campbell, eds., TMS, Warrendale, PA, 1995, pp. 303–10.Google Scholar
- 17.M. Rappaz, J.M. Drezet, and M. Gremaud: Metall. Mater. Trans. A, 1999, vol. 30A, pp. 449–55.Google Scholar
- 18.Suyitno, W.H. Kool, and L. Katgerman: Mater. Sci. Forum, 2002, vols. 396–402, pp. 179–84.CrossRefGoogle Scholar
- 19.M. Braccini, C.L. Martin, and M. Suery: in Modeling of Casting Welding and Advanced Solidification Processes IX, P.R. Sahm, P.N. Hansen, and J.G. Conley, eds., Shaker Verlag, Aachen, 2000, pp. 18–24.Google Scholar
- 20.I. Farup and A. Mo: Metall. Mater. Trans. A, 2000, vol. 31A, pp. 1461–72.Google Scholar
- 21.M. M’Hamdi, A. Mo, and C.L. Martin: Metall. Mater. Trans. A, 2002, vol. 33A, pp. 2081–93.CrossRefGoogle Scholar
- 22.M.L. Nedreberg: Ph.D. Thesis, University of Oslo, Oslo, 1991.Google Scholar
- 23.J.M. Drezet and M. Rappaz: in Light Metals 2001, J.L. Anjier, ed., TMS, Warrendale, PA, 2001, pp. 887–93.Google Scholar
- 24.MSC. Marc Volume A: Theory and User Information, version 2000, MSC. Software 2000.Google Scholar
- 25.Suyitno, W.H. Kool, and L. Katgerman: in Light Metals 2003, P.N. Crepeau, ed., TMS, Warrendale, PA, 2003, pp. 753–58.Google Scholar
- 26.Suyitno, L. Katgerman, and A. Burghardt: Proc. ASME Heat Transfer Division—2002, T. Bayazitoglu and H.S. Cameron, eds., ASME, New York, NY, 2002, vol. 5, pp.147–54.Google Scholar
- 27.J. Zuidema, L. Katgerman, I.J. Opstelten, and J.M. Rabenberg: in Light Metals 2001, J.L. Anjier, ed., TMS, Warrendale, PA, 2001, pp. 873–79.Google Scholar
- 28.Y.S. Touloukian and E.H. Buyco: Thermophysical Properties of Matter, vol. 4, Specific Heat, Metallic Elements and Alloys, IFI/Plenum Press, New York, NY, 1970.Google Scholar
- 29.R.E. Taylor, H. Groot, T. Goerz, J. Ferrier, and D.L. Taylor: High Temp.-High Pressure, 1998, vol. 30, pp. 269–75.CrossRefGoogle Scholar
- 30.R.A. Overfelt, S.I. Bakhtiyarov, and R.E. Taylor: High Temp.-High. Pressure, 2002, vol. 34, pp. 401–09.CrossRefGoogle Scholar
- 31.J.A. Brammer and C.M. Percival: Exp. Mech., 1970, vol. 10, pp. 245–50.CrossRefGoogle Scholar
- 32.W.-M. van Haaften: Empact Report on Thermophysical Properties of EMPACT Alloys, Subtask 2.1, Delft University of Technology, Delft, The Netherlands, October 1997.Google Scholar
- 33.J. Hutt and D. StJohn: Int. J. Cast Met. Res., 1998, vol. 11, pp. 13–22.Google Scholar
- 34.B.C.H. Venneker and L. Katgerman: J. Light Met., 2002, vol. 2, pp. 149–59.CrossRefGoogle Scholar
- 35.L. Backerud, E. Król, and J. Tamminen: Solidification Characteristics of Aluminium Alloys, vol. 1, Wrought Alloys, Skanaluminium/Universitetsforlaget AS, Oslo, 1986.Google Scholar
- 36.D.G. Eskin, Suyitno, J. Mooney, and L. Katgerman: Metall. Mater. Trans. A, 2004, vol. 35A, pp. 1325–35.Google Scholar
- 37.B. Commet, P. Delaire, J. Rabenberg, and J. Storm: in Light Metals 2003, P.N. Crepeau, ed., TMS, Warrendale, PA, 2003, pp. 711–17.Google Scholar
- 38.M. M’Hamdi, S. Benum, D. Mortensen, H.G. Fjaer, and J.-M. Drezet; Metall. Mater. Trans. A, 2003, vol. 34A, pp. 1941–52.Google Scholar