CORRELATION OF HARDNESS AND SILICON MORPHOLOGY FOR Al-Si-Sb ALLOY


Uzun O., Yilmaz F., Emeksiz C., Ergen S., Kolemen U.

ARCHIVES OF METALLURGY AND MATERIALS, vol.63, no.1, pp.467-472, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 63 Issue: 1
  • Publication Date: 2018
  • Doi Number: 10.24425/118963
  • Title of Journal : ARCHIVES OF METALLURGY AND MATERIALS
  • Page Numbers: pp.467-472
  • Keywords: Al-Si alloy, casting, Vickers, finite element analysis, MECHANICAL-PROPERTIES, AL-20SI-5FE ALLOYS, AL-12SI ALLOY, MICROSTRUCTURE, NA, SR

Abstract

In this study, we have focused on the role of silicon morphology on the hardness of eutectic Al - 12 wt.% Si - 0.5 wt.% Sb alloy solidified at different cooling rates. The alloys were produced by using induction melting, arc-remelting and melt-spinning techniques. The cooling rates of the alloys were determined as 0.5, 60 and similar to 10(5)degrees C.s(-1) for induction-melted, arc-remelted and melt-spun alloy. The experimental results show that as the cooling rate increased the coarse silicon phase was substantially refined and its morphology altered from sharp need-like to round shape. Two exothermic peaks, attributed to precipitation and coarsening of silicon from supersaturated alpha-Al, were observed in the DSC curve of MS alloy. Vicker's hardness of melt-spun alloy was found two times higher than those of IMed and ARed alloys. The lowest hardness of induction-melted alloy was ascribed to the lamellar morphology of silicon, yielding decohesive rupture. This result was confirmed by finite element analyzing.