Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)
- Volume 20 Issue 7
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- Pages.2367-2374
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- 1996
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- 1226-4881(pISSN)
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- 2288-5324(eISSN)
DOI QR Code
A generalized scheil equation for the dendritic solidification of binary alloys
이원합금의 수지상응고에 대한 일반화된 Scheil식
- Yu, Ho-Seon (Dept.of Mechanical Engineering, Soongsil University)
- 유호선 (숭실대학교 기계공학과)
- Published : 1996.07.01
Abstract
A generalized Scheil equation for the solute redistribution in the absence of the back diffusion during the dendritic solidification of binary alloys is derived, in which coarsening of the secondary dendrite arms is taken into account. The obtained equation essentially includes the original Scheil equation as a subset. Calculated results for typical cases show that the coarsening affects the microsegregation significantly. The eutectic fraction predicted for coarsening is considerably smaller than that for fixed arm spacing. The most important feature of the present equation in comparison with the Scheil equation lies in the fact that there exists a lower limit of the initial composition below which the eutectic is not formed. Based on the generalized Scheil equation and the lever rule, a new regime map of the eutectic formation on the initial composition-equilibrium partition coefficient plane is proposed. The map consists of three regimes: the eutectic not formed, conditionally formed and unconditionally formed, bounded by the solubility and diffusion controlled limit lines.
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