Abstract
The distribution characteristic and segregation behavior of metal impurities during directional solidification of Al-20Si, Al-30Si and Al-40Si alloys have been investigated. The morphologies of the alloys and impurity phases were observed by optical microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The concentration profiles of representative metal impurities Al, Fe and Ti were measured by inductively coupled plasma optical emission spectrometry. The results indicate that the metal impurities segregate into the eutectic Al-Si melt during the growth of primary Si flakes and gradually segregate towards the top of each ingot during directional solidification. A concept of apparent segregation coefficient is proposed to characterize the segregation behavior of impurity elements. The apparent segregation coefficients of metal impurities decrease with increase in solidification temperature of the Al-Si alloys.
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Acknowledgements
This work was supported by the Key Laboratory of Photovolatic and Energy Conservation Materials, Chinese Academy of Sciences and financially supported by National Natural Science Foundation of China (No. 51474201 and No. 51404231); Anhui Provincial Natural Science Foundation (No. 1508085QE81); CPSF-CAS Joint Foundation for Excellent Postdoctoral Fellows (No. 2016LH0017); China Postdoctoral Science Foundation (No. 2014M561846); CASHIPS Director’s Funds (Grant No. YYJJ201624); 100 Talent Program of Chinese Academy of Sciences(No. 2012065).
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Bai, X., Ban, B., Li, J. et al. Segregation Behavior of Metal Impurities During Al-Si Melt Directional Solidification with an Open Ended Crucible. Silicon 10, 1283–1290 (2018). https://doi.org/10.1007/s12633-017-9602-5
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DOI: https://doi.org/10.1007/s12633-017-9602-5