Article – Effect of Modification with Different Contents of Sb and Sr on the Thermal Conductivity of Hypoeutectic Al-Si Alloy


Effect of Modification with Different Contents of Sb and Sr on the Thermal Conductivity of Hypoeutectic Al-Si Alloy



Abstract :

In this paper, the effects of size, morphology and distribution of eutectic silicon on the thermal conductivity of Al-8Si alloy modified by Sr (0.04, 0.08, 0.12 wt.%) and Sb (0.1, 0.3, 0.5 wt.%) elements with T6 heat treatment were investigated. The results show that the modified fibrous eutectic silicon has a significant capability of improvement of thermal conductivity, while the amount of the modifier has a relatively weak effect on thermal conductivity. After T6 treatment, the fracture or spheroidization of the flake eutectic silicon and the disappearance of clustering phenomenon could raise thermal conductivity, but the coarsening of fibrous eutectic silicon is inconducive to thermal conductivity. Finally, the effect of eutectic silicon on electron transport is analyzed in detail, which could provide a reference for enhancing the thermal (or electrical) conductivity of hypoeutectic Al-Si alloy through effective microstructure control.



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References :

  1. Abdollahi, A.; Gruzleski, J.E. An evaluation of calcium as a eutectic modifier in A357 alloy. Int. J. Cast Met. Res. 1998, 11, 145–155.
  2. Cui, X.; Cui, H.; Wu, Y.; Liu, X. The improvement of electrical conductivity of hypoeutectic Al-Si alloys achieved by composite melt treatment. J. Alloy. Compd. 2019, 788, 1322–1328.
  3. Li, K.; Li,W.; Zhang, G.; Zhu,W.; Zheng, F.; Zhang, D.;Wang, M. Effects of Si phase refinement on the plasma electrolytic oxidation of eutectic Al-Si alloy. J. Alloy. Compd. 2019, 790, 650–656.
  4. Shaji, M.C.; Ravikumar, K.K.; Ravi, M.; Sukumaran, K. Development of a high strength cast aluminium alloy for possible automotive applications. Mater. Sci. Forum 2013, 765, 54–58.
  5. Rauta, V.; Cingi, C.; Orkas, J. Effect of annealing and metallurgical treatments on thermal conductivity of aluminium alloys. Int. J. Met. 2016, 10, 157–171.
  6. Stadler, F.; Antrekowitsch, H.; Fragner,W.; Kaufmann, H.; Pinatel, E.R.; Uggowitzer, P.J. The effect of main alloying elements on the physical properties of Al–Si foundry alloys. Mater. Sci. Eng. A 2013, 560, 481–491.
  7. Cui, X.; Wu, Y.; Liu, X.; Zhao, Q.; Zhang, G. Effects of grain refinement and boron treatment on electrical conductivity and mechanical properties of AA1070 aluminum. Mater. Des. 2015, 86, 397–403.
  8. Cui, X.;Wu, Y.; Zhang, G.; Liu, Y.; Liu, X. Study on the improvement of electrical conductivity and mechanical properties of low alloying electrical aluminum alloys. Compos. Part B Eng. 2017, 110, 381–387.
  9. Khaliq, A.; Rhamdhani, M.A.; Brooks, G.A.; Grandfield, J.F. Removal of vanadium from molten aluminum—Part II. Kinetic analysis and mechanism of VB2 formation. Metall. Mater. Trans. B 2014, 45, 769–783.
  10. Cui, X.; Wu, Y.; Cui, H.; Zhang, G.; Zhou, B.; Liu, X. The improvement of boron treatment efficiency andelectrical conductivity of AA1070Al achieved by trace Ti assistant. J. Alloy. Compd. 2018, 735, 62–67.
  11. Mulazimoglu, M.H.; Drew, R.A.L.; Gruzelski, J.E. Electrical conductivity of aluminium-rich Al-Si-Mg alloys. J. Mater. Sci. Lett. 1989, 8, 297–300.
  12. Mulazimoglu, M.H.; Drew, R.A.L.; Gruzleski, J.E. The electrical conductivity of cast Al−Si alloys in the range 2 to 12.6 wt pct silicon. Metall. Trans. A 1989, 20, 383–389.
  13. Narayan Prabhu, K.; Ravishankar, B.N. Effect of modification melt treatment on casting/chill interfacial heat transfer and electrical conductivity of Al–13% Si alloy. Mater. Sci. Eng. A 2003, 360, 293–298.
  14. Lumley, R.N.; Polmear, I.J.; Groot, H.; Ferrier, J. Thermal characteristics of heat-treated aluminum high-pressure die-castings. Scripta Materialia 2008, 58, 1006–1009.
  15. Choi, S.W.; Cho, H.S.; Kang, C.S.; Kumai, S. Precipitation dependence of thermal properties for Al–Si–Mg–Cu–(Ti) alloy with various heat treatment. J. Alloy. Compd. 2015, 647, 1091–1097.
  16. Lados, D.A.; Apelian, D.;Wang, L. Solution treatment effects on microstructure and mechanical properties of Al-(1 to 13 pct)Si-Mg cast alloys. Metall. Mater. Trans. B 2010, 42, 171–180.
  17. Vandersluis, E.; Ravindran, C. Effects of solution heat treatment time on the as-quenched microstructure, hardness and electrical conductivity of B319 aluminum alloy. J. Alloy. Compd. 2020, 838.
  18. Tiedje, N.S.; Taylor, J.A.; Easton, M.A. A new multi-zone model for porosity distribution in Al–Si alloy castings. Acta Mater. 2013, 61, 3037–3049.
  19. Barrirero, J.; Li, J.; Engstler, M.; Ghafoor, N.; Schumacher, P.; Odén, M.; Mücklich, F. Cluster formation at the Si/liquid interface in Sr and Na modified Al–Si alloys. Scripta Mater. 2016, 117, 16–19.
  20. Li, J.H.;Wang, X.D.; Ludwig, T.H.; Tsunekawa, Y.; Arnberg, L.; Jiang, J.Z.; Schumacher, P. Modification of eutectic Si in Al–Si alloys with Eu addition. Acta Mater. 2015, 84, 153–163.
  21. Rao, J.; Zhang, J.; Liu, R.; Zheng, J.; Yin, D. Modification of eutectic Si and the microstructure in an Al-7Si alloy with barium addition. Mater. Sci. Eng. A 2018, 728, 72–79.
  22. Li, B.; Wang, H.; Jie, J.; Wei, Z. Effects of yttrium and heat treatment on the microstructure and tensile properties of Al–7.5 Si–0.5 Mg alloy. Mater. Des. 2011, 32, 1617–1622.
  23. Farahany, S.; Ourdjini, A.; Idrsi, M.H.; Shabestari, S.G. Evaluation of the effect of Bi, Sb, Sr and cooling condition on eutectic phases in an Al–Si–Cu alloy (ADC12) by in situ thermal analysis. Thermochimica Acta 2013, 559, 59–68.
  24. Darlapudi, A.; McDonald, S.D.; Terzi, S.; Prasad, A.; Felberbaum, M.; StJohn, D.H. The influence of ternary alloying elements on the Al–Si eutectic microstructure and the Si morphology. J. Cryst. Growth 2016, 433, 63–73
  25. Olafsson, P.; Sandstrom, R.; Karlsson, Å. Comparison of experimental, calculated and observed values for electrical and thermal conductivity of aluminium alloys. J. Mater. Sci. 1997, 32, 4383–4390
  26. Lumley, R.N.; Deeva, N.; Larsen, R.; Gembarovic, J.; Freeman, J. The role of alloy composition and T7 heat treatment in enhancing thermal conductivity of aluminum high pressure diecastings. Metall. Mater. Trans. A Phys. Metall. Mater. Sci. 2013, 44, 1074–1086.
  27. Cho, Y.H.; Kim, H.W.; Lee, J.M.; Kim, M.S. A new approach to the design of a low Si-added Al-Si casting alloy for optimising thermal conductivity and fluidity. J. Mater. Sci. 2015, 50, 7271–7281.
  28. Vandersluis, E.; Lombardi, A.; Ravindran, C.; Bois-Brochu, A.; Chiesa, F.; MacKay, R. Factors influencing thermal conductivity and mechanical properties in 319 Al alloy cylinder heads. Mater. Sci. Eng. A 2015, 648, 401–411.
  29. Dinnis, C.M.; Taylor, J.A.; Dahle, A.K. As-cast morphology of iron-intermetallics in Al–Si foundry alloys. Scripta Materialia 2005, 53, 955–958.
  30. Faraji, M.; Katgerman, L. Distribution of trace elements in a modified and grain refined aluminium–silicon hypoeutectic alloy. Micron 2010, 41, 554–559.
  31. Simensen, C.J.; Nielsen, Ø.; Hillion, F.; Voje, J. NanoSIMS Analysis of trace element segregation during the Al-Si eutectic reaction. Metall. Mater. Trans. A 2007, 38, 1448–1451
  32. Lu, S.Z.; Hellawell, A. The mechanism of silicon modification in aluminum-silicon alloys: Impurity induced twinning. Metall. Trans. A 1987, 18, 1721–1733.
  33. Nogita, K.; Yasuda, H.; Yoshida, K.; Uesugi, K.; Takeuchi, A.; Suzuki, Y.; Dahle, A.K. Determination of strontium segregation in modified hypoeutectic Al–Si alloy by micro X-ray fluorescence analysis. Scripta Materialia 2006, 55, 787–790.
  34. Nogita, K.; Yasuda, H.; Yoshiya, M.; McDonald, S.D.; Uesugi, K.; Takeuchi, A.; Suzuki, Y. The role of trace element segregation in the eutectic modification of hypoeutectic Al–Si alloys. J. Alloy. Compd. 2010, 489, 415–420.
  35. Lu, S.-Z.; Hellawell, A. Growth mechanisms of silicon in Al-Si alloys. J. Cryst. Growth 1985, 73, 316–328.
  36. Hansen, S.C.; Loper, C.R. Effect of antimony on the phase equilibrium of binary Al-Si alloys. Calphad 2000, 24, 339–352.
  37. Xiufang, B.;Weimin,W.; Jingyu, Q. Liquid structure of Al–12.5% Si alloy modified by antimony. Mater. Charact. 2001, 46, 25–29.
  38. Gustafsson, G.; Thorvaldsson, T.; Dunlop, G.L. The influence of Fe and Cr on the microstructure of cast Al-Si-Mg alloys. Metall. Trans. A 1986, 17, 45–52.
  39. Mohamed, A.M.A.; Samuel, A.M.; Samuel, F.H.; Doty, H.W. Influence of additives on the microstructure and tensile properties of near-eutectic Al–10.8%Si cast alloy. Mater. Des. 2009, 30, 3943–3957.
  40. Zhao, Q.; Qian, Z.; Cui, X.;Wu, Y.; Liu, X. Optimizing microstructures of dilute Al–Fe–Si alloys designed with enhanced electrical conductivity and tensile strength. J. Alloy. Compd. 2015, 650, 768–776.
  41. Hou, J.P.; Li, R.; Wang, Q.; Yu, H.Y.; Zhang, Z.J.; Chen, Q.Y.; Ma, H.; Wu, X.M.; Li, X.W.; Zhang, Z.F.; et al. Breaking the trade-off relation of strength and electrical conductivity in pure Al wire by controlling texture and grain boundary. J. Alloy. Compd. 2018, 769, 96–109.
  42. Karabay, S. Modification of AA-6201 alloy for manufacturing of high conductivity and extra high conductivity wires with property of high tensile stress after artificial aging heat treatment for all-aluminium alloy conductors. Mater. Des. 2006, 27, 821–832.