Enhancing impurities removal from Si by controlling crystal growth in directional solidification refining with Al-Si alloy

doi:10.1016/j.jallcom.2019.153300

	Enhancing impurities removal from Si by controlling crystal growth in directional solidification refining with Al-Si alloy
	Qian, Guoyu 1; Sun, Liyuan 1; Chen, Hang 1; Wang, Zhi 1; Wei, Kuixian 2; Ma, Wenhui 2
刊名	JOURNAL OF ALLOYS AND COMPOUNDS
	2020-04-15
卷号	820 页码:10
关键词	High purity silicon Directional solidification Al-Si solvent refining Si crystal growth Impurity removal
ISSN号	0925-8388
DOI	10.1016/j.jallcom.2019.153300
英文摘要	In this paper, the principle of "plain materials" was attempted to advancing silicon (Si) purity, i.e., controlling solid-liquid interface and Si crystal growth pattern to enhance impurities removal from Si in directional solidification refining with Al-Si alloy. The relationship between Si crystal growth and impurity removal was established, and it was found that the removal ratio of metal impurities (less than 95% to more than 99%) gradually decreased with the order evolution of Si crystal from bulk Si, porous Si, acicular Si to Al-Si eutectic alloy. More than 99.5% of metallic impurities could be removed in the case of bulk silicon. However, the removal of boron (B) and phosphorus (P) showed the opposite trend. According to the principle of constitutional supercooling, the crystal Si growth and interface morphology were evaluated based on the conservation of mass of silicon atoms at the solidification interface, which was also used to explain the mechanism of impurities removal. Control of silicon crystal growth was achieved by changing the temperature gradient (lowering rate), Si alloy composition (Si content) and the heat transfer mode of solid-liquid interface that was expressed in terms of the effective heat transfer area ratio between wall and bottom of crucible (L-A). A more stable and flat liquid-solid interface and 45% bulk Si was obtained at a lowering rate of 0.05 mm/min when the value of L-A was 0.1, which can greatly enhance the removal of impurities. (C) 2019 Elsevier B.V. All rights reserved.
资助项目	National Key R&D Program of China[2018YFC1901801] ; National Natural Science Foundation of China[U1702251] ; National Natural Science Foundation of China[51604256] ; Beijing Municipal Natural Science Foundation[2192055]
WOS关键词	METALLURGICAL-GRADE SILICON ; BORON REMOVAL ; PURIFICATION ; SEPARATION ; MELT ; THERMODYNAMICS ; PHOSPHORUS ; CALCIUM ; GETTER ; FIELD
WOS研究方向	Chemistry ; Materials Science ; Metallurgy & Metallurgical Engineering
语种	英语
出版者	ELSEVIER SCIENCE SA
WOS记录号	WOS:000507854700051
资助机构	National Key R&D Program of China ; National Natural Science Foundation of China ; Beijing Municipal Natural Science Foundation
内容类型	期刊论文
源URL	[http://ir.ipe.ac.cn/handle/122111/38693]
专题	中国科学院过程工程研究所
通讯作者	Wang, Zhi
作者单位	1.Chinese Acad Sci, Inst Proc Engn, Key Lab Green Proc & Engn, Natl Engn Lab Hydromet Cleaner Prod Technol, Beijing 100190, Peoples R China 2.Kunming Univ Sci & Technol, Fac Met & Energy Engn, Kunming 650093, Yunnan, Peoples R China
推荐引用方式 GB/T 7714	Qian, Guoyu,Sun, Liyuan,Chen, Hang,et al. Enhancing impurities removal from Si by controlling crystal growth in directional solidification refining with Al-Si alloy[J]. JOURNAL OF ALLOYS AND COMPOUNDS,2020,820:10.
APA	Qian, Guoyu,Sun, Liyuan,Chen, Hang,Wang, Zhi,Wei, Kuixian,&Ma, Wenhui.(2020).Enhancing impurities removal from Si by controlling crystal growth in directional solidification refining with Al-Si alloy.JOURNAL OF ALLOYS AND COMPOUNDS,820,10.
MLA	Qian, Guoyu,et al."Enhancing impurities removal from Si by controlling crystal growth in directional solidification refining with Al-Si alloy".JOURNAL OF ALLOYS AND COMPOUNDS 820(2020):10.