Advertisement

Effects of Melt Superheating on the Microstructure and Tensile Properties of a Ternary Al-15 Wt Pct Si-1.5 Wt Pct Mg Alloy

  • Rafael Kakitani
  • Rodrigo V. Reyes
  • Amauri Garcia
  • Noé Cheung
  • José E. Spinelli
Article
  • 38 Downloads

Abstract

Unsteady solidified microstructures of the Al-15 wt pct Si-1.5 wt pct Mg alloy under two degrees of melt superheating are examined: 4 and 21 pct above the alloy liquidus temperature. The dendritic array and the eutectic mixture have been investigated, which are affected not only by the solidification kinetics but also by the melt superheating. The directional solidification experiments permitted that aligned Al-rich dendrites could be formed for both high- and low-melt superheatings. These dendrites appear as ‘islands’ isolated from each other and dispersed within the α-Al+Si+Mg2Si eutectic matrix. Such configuration arises in samples under the entire range of examined cooling rates, i.e., from 0.5 to 50 K/s. Directionally solidified samples having different α-Al dendrite interphase spacings have been characterized and subjected to tensile tests. Such microstructural spacings translate the effectiveness in blocking the dislocations motion during loading, which is promoted mainly by the dendritic/eutectic boundaries. This mechanism is especially operative since the applied tensile load is perpendicular to the dendritic growth path. As such, the evolution of tensile properties as a function of these spacings was assessed. Both elongation (δ) and the ultimate strength (σu) are enhanced nearly by 40 pct due to the reduction in the dendrite interphase spacing. The highest properties (σu: ~ 310 MPa and δ: ~ 7 pct) are associated with a microstructure formed by aligned dendrites with 70 μm in spacing embedded in a eutectic mixture. Three factors appear to contribute to the higher strength values observed for the alloy processed under lower-melt superheating, i.e., higher fraction of dendrites, solid solution strengthening of Mg in α-Al, and finer eutectic Si spacing.

Notes

Acknowledgments

The authors are grateful to FAPESP (São Paulo Research Foundation, Brazil: grant 2017/12741-6) and National Council for Scientific and Technological Development – CNPq for their financial support.

References

  1. 1.
    [1] P. Pandey, S. Kashyap, CS. Tiwary, K Chattopadhyay: Metall Mater Trans A, 2017, vol. 48, pp. 5940-5950.CrossRefGoogle Scholar
  2. 2.
    J.W. Bray: ASM Metals Handbook, 10th ed., ASM International, Ohio, 1976Google Scholar
  3. 3.
    V.S. Zolotorevsky, N.A Belov, M.V. Glazoff: Casting Aluminum Alloys, vol. 12, Elsevier, Amsterdam, 2007.Google Scholar
  4. 4.
    [4] R.V. Reyes, TS Bello, R Kakitani, TA Costa, A Garcia, N Cheung, JE Spinelli: Mater Sci Eng A, 2017, vol. 685, pp. 235-243.CrossRefGoogle Scholar
  5. 5.
    [5] M. Tebib, F Ajersch, AM Samuel, X-G Chen: Metall Mater Trans, 2013, vol. 44, pp. 4282-4295.CrossRefGoogle Scholar
  6. 6.
    [6] K Matsuura, M Kudoh, H Kinoshita: Mater Chem Phys, 2003, vol. 81, pp. 393-395.CrossRefGoogle Scholar
  7. 7.
    [7] L Lasa, JM Rodriguez-Ibabe: Mater Sci Eng A, 2003, vol. 363, pp. 193-202.CrossRefGoogle Scholar
  8. 8.
    [8] E. Sjölander, S.Seifeddine: J. Mater. Process. Technol., 2010, vol. 210, pp. 1249-1259.CrossRefGoogle Scholar
  9. 9.
    D.L. Zhang, L.H. Zheng, D.H. Stjohn: J. Light Met., 2002, vol. 2, pp. 27-36.CrossRefGoogle Scholar
  10. 10.
    [10] L.G. Hou, H. Cui, Y.H. Cai, J.S. Zhang: Mater. Sci. Eng. A, 2009, vol. 527, pp. 85-92.CrossRefGoogle Scholar
  11. 11.
    [11] E.R. Wang, X.D. Hui, G.L. Chen: Mater. Des., 2011, vol. 32, pp. 4333-4340.CrossRefGoogle Scholar
  12. 12.
    A. Mandal, M.M. Makhlouf: Improving Aluminum Casting Alloy and Process Competitiveness, Report no. 07-02, ACRC, Durango, 2007.Google Scholar
  13. 13.
    A. Mandal, M.M. Makhlouf: Proceedings of 113th TMS Annual Meeting, San Francisco, 2009, pp. 57-62.Google Scholar
  14. 14.
    [14] A Mandal, MM Makhlouf: Int J Cast Metal Res, 2010, vol. 23, pp. 303-309.CrossRefGoogle Scholar
  15. 15.
    [15] A Hekmat-Ardakan, F Ajersch: J Mater Process Tech, 2010, vol. 210, pp. 767-775.CrossRefGoogle Scholar
  16. 16.
    [16] Y. Wu, H. Liaon, K. Zhou: Mater. Sci. Eng. A, 2014, vol. 602, pp. 41-48.CrossRefGoogle Scholar
  17. 17.
    [17] A. Niklas, A. Bakedano, S. Orden, M. da Silva, E. Nogués, A.I. Fernández-Calvo: Materials Today: Proceedings, 2015, vol. 2, pp. 4931-4938.CrossRefGoogle Scholar
  18. 18.
    [18] S. Seifeddine, S. Johansson, I.L. Svensson: Mater. Sci. Eng. A, 2008, vol. 490, pp. 385-390.CrossRefGoogle Scholar
  19. 19.
    [19] PR Goulart, WR Osório, JE Spinelli, A Garcia: Mater Manuf Process, 2007, vol. 22, pp. 328-332.CrossRefGoogle Scholar
  20. 20.
    [20] PR Goulart, JE Spinelli, WR Osorio, A Garcia: Mater. Sci. Eng. A, 2006, vol. 421, pp. 245-253.CrossRefGoogle Scholar
  21. 21.
    E. Ghassemali, M. Riestra, T. Bogdanoff, B.S. Kumar, S. Seifeddine: International Conference on the Technology of Plasticity, ICTP, Cambridge, 2017, pp. 17–22.Google Scholar
  22. 22.
    [22] J Zhang, Z Fan, YQ Wang, BL Zhou: Mater. Sci. Eng. A, 2000, vol. 281, pp.104-122.CrossRefGoogle Scholar
  23. 23.
    [23] QC Jiang, HY Wang, Y Wang, BX Ma, JG Wang: Mater. Sci. Eng. A, 2005, vol. 392, pp. 130-135.CrossRefGoogle Scholar
  24. 24.
    [24] R Hadian, M Emamy, N Varahram, N Nemati: Mater. Sci. Eng. A, 2008, vol. 490, pp. 250-257.CrossRefGoogle Scholar
  25. 25.
    [25] QD Qin, WX Li, KW Zhou, SL Qiu, YG Zhao, Mater. Sci. Eng. A, 2011, vol. 527, pp. 2253–2257.CrossRefGoogle Scholar
  26. 26.
    A. Kearney and E.L. Rooy: ASM Handbook - Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook Committee, 1990, vol. 2, pp. 123–151.Google Scholar
  27. 27.
    M. Okayasu, S. Takeuchi, T. Shiraishi: Int. J. Cast. Metal. Res., 2013, vol. 26, pp.105-113CrossRefGoogle Scholar
  28. 28.
    [28] Z. Qian, X. Liu, D. Zhao, G. Zhang: Mater. Lett., 2008, vol. 62, pp. 2150–2153.CrossRefGoogle Scholar
  29. 29.
    [29] M. V. Canté, J. E. Spinelli, N. Cheung, A. Garcia: Met. Mater. Int., 2010, vol. 16, pp. 39-49.CrossRefGoogle Scholar
  30. 30.
    [30] DM Rosa, JE Spinelli, IL Ferreira, A Garcia: J Alloys Compd, 2006, vol. 422, pp.227-238.CrossRefGoogle Scholar
  31. 31.
    [31] M. Gunduz, E. Çadirli: Mater. Sci. Eng. A, 2002, vol. 327, pp. 167-185.CrossRefGoogle Scholar
  32. 32.
    [32] E. Çadirli, U. Büyük, S. Engin, H. Kaya. J. Alloys Compd., 2017, vol. 694, pp. 471-479.CrossRefGoogle Scholar
  33. 33.
    [33] K.A. Jackson, J.D. Hunt: Trans. Metall. Soc. AIME, 1966, vol. 236, pp. 1129-1142.Google Scholar
  34. 34.
    [34] Y. Birol: Mater. Sci. Eng. A, 2013, vol. 559, pp. 394-400.CrossRefGoogle Scholar
  35. 35.
    [35] E. Samuel, B. Golbahar, A.M. Samuel, H.W. Doty, S. Valtierra, F.H. Samuel: Mater. Des., 2014, vol. 56, pp. 468-479.CrossRefGoogle Scholar
  36. 36.
    E.L. Rooy: Aluminum and Aluminum Alloys, Casting 9th edition, vol. 15, Metals Handbook, ASM international, 1988, pp. 743–70.Google Scholar
  37. 37.
    [37] G Zhang, J Zhang, B Li, W Cai: Prog Nat Sci-Mater, 2011, vol. 21, pp. 380-385.CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2018

Authors and Affiliations

  • Rafael Kakitani
    • 1
  • Rodrigo V. Reyes
    • 2
  • Amauri Garcia
    • 1
  • Noé Cheung
    • 1
  • José E. Spinelli
    • 2
  1. 1.Department of Manufacturing and Materials EngineeringUniversity of Campinas UNICAMPCampinasBrazil
  2. 2.Department of Materials EngineeringFederal University of São CarlosSão CarlosBrazil

Personalised recommendations