Journal of Thermal Analysis and Calorimetry

, Volume 133, Issue 1, pp 123–133 | Cite as

Interaction of Ca, P trace elements and Sr modification in AlSi5Cu1Mg alloys



Thermal and microscopy analyses were carried out to investigate the interaction of Sr modification with Ca and P trace elements in high-purity and commercial-purity Al–5Si–1Cu–Mg alloys. The results show how the addition of Sr to commercial-purity alloy induces significant changes in the nucleation and growth temperatures of eutectic Si since pre-eutectic Al2Si2(CaSr) intermetallics tend to poison AlP particles, making them inactive as nucleation sites for eutectic Si. In contrast, the addition of Sr to high-purity alloy shows no apparent influence on the characteristic temperatures of Al–Si eutectic reaction, even though the microstructural investigations reveal flake-to-fibrous transition in the eutectic Si structure. This indicates that the eutectic growth temperature, commonly used to predict eutectic modification level, is not a key feature of Sr modification, but it is indirectly caused due to the presence of additional impurities in commercial-purity alloys which affect the nucleation kinetics of eutectic Si.


Aluminium alloys C355 Eutectic modification Foundry Microstructure Thermal analysis 



The authors would like to acknowledge Dr. A. Fabrizi for his precious work to perform experiments and characterizations.


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2018

Authors and Affiliations

  1. 1.Department of Management and EngineeringUniversity of PadovaVicenzaItaly
  2. 2.Department of Mechanical EngineeringNavoi State Mining InstituteNavoiUzbekistan

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