Journal of Thermal Analysis and Calorimetry

, Volume 114, Issue 2, pp 705–717 | Cite as

Computer-aided cooling curve thermal analysis of near eutectic Al–Si–Cu–Fe alloy

Effect of silicon modifier/refiner and solidification conditions on the nucleation and growth of dendrites
  • S. FarahanyEmail author
  • A. Ourdjini
  • M. H. Idris
  • S. G. Shabestari


The effects of bismuth (Bi), antimony (Sb) and strontium (Sr) additions on the characteristic parameters of the evolution of aluminium dendrites in a near eutectic Al–11.3Si–2Cu–0.4Fe alloy during solidification at different cooling rates (0.6–2 °C) were investigated by computer-aided cooling curve thermal analysis (CA-CCTA). Nucleation temperature (\( T_{\text{N}}^{{\alpha {\text{ - Al}}}} \)) is defined with a new approach based on second derivative cooling curve. The results showed that \( T_{\text{N}}^{{\alpha {\text{ - Al}}}} \) increased with increasing cooling rate but both the growth temperature (\( T_{\text{G}}^{{\alpha {\text{ - Al}}}} \)) and the coherency temperature (T DCP) decreased. Increase in the temperature difference for dendrite coherency (\( T_{\text{N}}^{{\alpha {\text{ - Al}}}} - T_{\text{DCP}} \)) with increasing cooling rate indicate a wider range of temperature before the dendrite can impinge on each other and higher fraction solid (\( f_{\text{S}}^{\text{DCP}} \)). Additions of Bi, Sb and Sr to the base alloy produced only a minor effect on \( T_{\text{N}}^{{\alpha {\text{ - Al}}}} \). Additions of Bi and Sb resulted in an increase in fraction solid and an increase of 30 % in the value of \( T_{\text{N}}^{{\alpha {\text{ - Al}}}} \, - \,T_{\text{G}}^{{\alpha {\text{ - Al}}}} \) to almost 13 °C.


Aluminium alloy Bismuth Solidification Thermal analysis Second derivative curve Coherency point 



The authors would like to thank Universiti Teknologi Malaysia for the provision of research facilities and the ministry of higher education (MOHE) for financial support under the GUP vote 02H17.


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2013

Authors and Affiliations

  • S. Farahany
    • 1
    Email author
  • A. Ourdjini
    • 1
  • M. H. Idris
    • 1
  • S. G. Shabestari
    • 2
  1. 1.Department of Materials Engineering, Faculty of Mechanical EngineeringUniversiti Teknologi Malaysia (UTM)Johor BahruMalaysia
  2. 2.Center of Excellence for High Strength Alloys Technology (CEHSAT), School of Metallurgy and Materials EngineeringIran University of Science and Technology (IUST)TehranIran

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