Journal of Korea Foundry Society (한국주조공학회지)

Korea Foundry Society (한국주조공학회)
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The Effect of Sr Addition and Mold Preheating Temperature on the Solidification and Microstructure of Al-7wt%Si-0.3wt%Mg Alloy

Al-7wt%Si-0.3wt%Mg 합금의 응고 및 미세조직에 미치는 Sr 첨가와 금형예열온도의 영향

  • Kwon, Il-Soo (Dept. of Metallurgical Engineering, Hanyang University) ;
  • Kim, Kyoung-Min (Dept. of Metallurgical Engineering, Hanyang University) ;
  • Yoon, Eui-Pak (Dept. of Metallurgical Engineering, Hanyang University)
  • 권일수 (한양대학교 금속공학과) ;
  • 김경민 (한양대학교 금속공학과) ;
  • 윤의박 (한양대학교 금속공학과)
  • Published : 1997.12.20
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Abstract

The effect of mold preheating temperature on the microstructure such as grain size, eutectic silicon morphology was investigated for the Al-7wt%Si-0.3wt%Mg alloy. Microstructural variations have been characterized as a function of Sr addition and cooling rate during solidification. Microstructures were correlated with cooling rate, local solidification time and eutectic nucleation temperature, etc. In this study, Sr addition caused increase of local solidification time, undercooling and reduction of eutectic plateau temperature. In logarithmic scale, local solidification time was in inverse proportion to cooling rate. Eutectic nucleation temperature was in inverse proportion to cooling rate of logarithmic scale. Increasing the cooling rate refined dendrite arm spacing and eutectic silicon. Dendrite arm spacing was logarithmically in inverse proportion to cooling rate. Without modifier addition, eutectic silicon was modified at cooling rate of $7^{\circ}C/s$ or higher.

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