Cellular Microstructure and Mechanical Properties of a Directionally Solidified Al-1.0wt%Fe Alloy

Abstract:

Upward directional transient solidification experiments have been carried out with an Al-1.0wt%Fe alloy. Tensile tests were carried out with samples collected along the casting length and these results have been correlated with measured cell spacings, since cellular growth has prevailed along the directionally solidified casting. The resulting mechanical properties include ultimate tensile strength, yield tensile strength and elongation. The used casting assembly was designed in such a way that the heat was extracted only through the water-cooled system at bottom of the casting. During non-equilibrium solidification, typical of DC (direct chill) castings, different cooling rates occur from the casting cooled surface up to the top of the casting, causing the formation of metastable intermetallic phases (AlmFe, Al6Fe, etc) in addition to the stable Al3Fe phase. The extensive presence of plate-like Al3Fe phase in the as-cast structure adversely influences the mechanical properties of Al-Fe alloys, since this morphology is more likely to induce microcracks than the fibrous Al6Fe phase. In order to permit an appropriate characterization of these intermetallic phases, they were extracted from the aluminum-rich matrix by using a dissolution technique. These phases were then investigated by optical microscopy and SEM techniques. It was found that the ultimate tensile strength, the yield strength and the elongation increase with decreasing cell spacing and experimental laws correlating cell spacing and these mechanical properties have been established.

• Periodical: Materials Science Forum (Volumes 636-637)
• Pages: 564-570
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.636-637.564
• Online since: January 2010
• Authors: Pedro R. Goulart, J.E. Spinelli, F. Bertelli, Wislei R.R. Osório, Noé Cheung, Amauri Garcia
• Keywords: Al-Fe Alloy, Cellular Microstructure, Mechanical Property

References

[1] C.M. Allen, S. Kumar, L. Carrol, K.A.Q. O'Reilly, H. Cama: Mater. Sci. Eng. A Vol. 304-306 (2001), p.604.

[2] C.A. Ahravci, M. O. Pekguleryuz: Calphad Vol. 22 (1998), p.147.

[3] P. Olaru, G. Gottstein, A. Pineau: Mater. Sci. Forum Vol. 550 (2007), p.247.

[4] L.F. Mondolfo: Aluminum alloys: Structure and Properties (Butterworth & Co. Ltd, London, England 1976).

[5] M. Gremaud, M. Carrard, W. Kurz: Acta Metall. Vol. 38 (1990), p.2587.

[6] M. Gremaud, M. Carrard, W. Kurz: Acta Metall. Mater. Vol 39 (1991), p.1431.

[7] P.R. Goulart, J.E. Spinelli, J. E., N. Cheung, I.L. Ferreira, A. Garcia: J. Alloys Compd. Vol. 470 (2009), p.589.

[8] M.V. Canté, J. E. Spinelli, I.L. Ferreira, N. Cheung, A. Garcia: Metall. Mater. Trans. A Vol. 39 (2008), p.1712.

[9] E. O. Hall: Yield Point Phenomena in Metals & alloys (Macmillan Co, London 1970).

[10] E. L. Rooy, in: Metals Handbook, Vol. 15, ASM International, Materials Park, Ohio (1988), p.743.

[11] P. Donelan: Mater. Sci. Technol. Vol. 16 (2000), p.261.

[12] J.M.V. Quaresma, C.A. Santos, A. Garcia: Metall. Mater. Trans. A Vol. 31 (2000), p.3167.

[13] P.R. Goulart, J.E. Spinelli, W.R. Osório, A. Garcia: Mater. Sci. Eng. A Vol. 421 (2006), p.245.

[14] G.A. Santos, C. Moura Neto, W.R. Osório, A. Garcia: Mater. Design Vol. 28 (2007), p.2425.

[15] W. R. Osório, P.R. Goulart, G.A. Santos, C. Moura Neto, A. Garcia: Metall. Mater. Trans. A Vol. 37 (2006), p.2525.

[16] C. M. Allen, K. A. Q. O'Reilly, B. Cantor, P. V. Evans: Prog. Mater. Sci. Vol. 43 (1998), p.89.

[17] A. Griger, V. Stefániay, E. Kovács-Csetényi, T. Turmezey: Key Eng. Mater. Vol. 44-45 (1990), p.17.

DOI: 10.4028/www.scientific.net/kem.44-45.17

[18] O. L. Rocha, C. A. Siqueira, A. Garcia, Metall. Mater. Trans. A Vol. 34 (2003), p.995.

[19] M. Gündüz, H. Kaya, E. Çardili, N. Marasli, K. Keslioglu, B. Saatçi: J. Alloys Compd. Vol. 439 (2007), p.114.

[20] ASTM E 8M - Standard Test Methods for Tension Testing of Metallic Materials. American Society of Testing and Materials, (1995).

[21] C.J. Simensen, A.I. Spjelkavik, Z. Fresenius: Anal. Chem. Vol. 300 (1980), p.177.

[22] C.J. Simensen, P. Fartum, A. Andersen, Z. Fresenius: Anal. Chem. Vol. 319 (1984), p.286.

[23] J.D. Hunt and K.A. Jackson: Trans. Met. Soc. AIME Vol. 236 (1966), p.843.

[24] I.R. Hughes, H. Jones: J. Mater. Sci. Vol. 11 (1976), p.1781.

[25] O.L. Rocha, C.A. Siqueira, A. Garcia: Mater. Sci. Eng. A Vol. 361 (2003), p.111.