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pISSN : 1598-706X / eISSN : 2288-8381


(논문)연구논문

한국주조공학회지 (11권4호 314-322)

A Study on the Effect of Modifiers Affecting the Modification of the Al-Si Alloys

Al-Si 합금의 개량화에 미치는 각종 개량화제의 영향에 관한 연구

Joon-Peuo Park*, Kyoung-Min Kim*, Soon-Hyung Cho*, Eui-Park Yoon*

*Hanyang Univ.

Abstract

In this study, Na, Li, Sb, Sr were added as the modifiers to improve the mechanical proper ties of Al-Si alloys and their effects were compared one another Thermal analysis was carried out to measure the degree of undercooling, that is, the basic mechanism of modifying effect. The measurements of holding time and analyses of components of Al-Si alloys were carried out to compare the fading of the modifiers. Greater degree of undercooling was measured from the modified alloy than the normal alloys. In the modified alloy, the shape of Si was changed into a fine fiber phase or a lamellar phase from the coarse plate phase. There are not modifying effect of Sb below the 1.5℃ /sec of cooling rate. As the cooling rate increases, similar effects appears in the non-modified alloys like the modified alloys. Na and Li were faded in short time and were difficult to control on the melt, but Sb and Sr were scarcely faded for 6 hours of holding and were easy to control on the melt. Na and Sr are the good modifiers in terms of microstructure. Sb is the best modifier, but Na, Li are the inadequate modifiers in terms of fading.

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