Preparation of high-purity TiSi2 and eutectic Si-Ti alloys by vacuum electromagnetic directional solidification
-
摘要: 为了制备高纯TiSi2和共晶Si-Ti合金，研究新采用真空电磁定向凝固技术对Ti-Si合金进行了相分离与提纯。结果表明，真空电磁定向凝固技术可以有效地提纯Ti-Si合金；Fe、Mn和Al杂质通过其在固-液界面上的分凝效应去除(富集在顶部)；Ca和Mg杂质由于蒸气压明显高于Si和Ti，因此可以通过真空挥发去除。Ti-56%Si合金(纯度96%)经真空电磁定向凝固后，在坩埚下部分离得到致密的TiSi2合金，而上部则分离得到物相均匀的共晶Si-Ti合金。由此制备的TiSi2纯度达到99.4%，共晶Si-Ti合金纯度达到99.1%(仅考虑主要杂质Fe、Mn、Ca、Mg和Al条件下)。Abstract: To prepare the high-purity TiSi2 and eutectic Si-Ti alloys, the vacuum electromagnetic directional solidification technique was used to separate and purify Ti-Si alloys in this study. The results show that the vacuum electromagnetic directional solidification can effectively purify the Ti-Si alloys. Fe, Al, and Mn impurities were removed through their segregation effect at the solid-liquid interface (enriched at the top). Ca and Mg impurities were removed by vacuum volatilization due to the vapor pressure being significantly higher than that of Si and Ti. After vacuum electromagnetically directed solidification of the Ti-56% Si alloy (purity 96%), the dense TiSi2 alloy was separated in the lower part of the crucible, and the eutectic Si-Ti alloy with a homogeneous phase was separated in the upper part. The purity of the TiSi2 thus prepared was 99.4%, and that of the eutectic Si-Ti alloy was 99.1% (only considering the main impurities Fe, Mn, Ca, Mg, and Al).
-
图 2 Ti-56%Si合金真空电磁定向凝固后，(a)合金纵截面的宏观图像和(b)~(g)合金在纵向位置的微观结构分析
Figure 2. (a) Macroscopic image of the longitudinal section of the alloy and (b)~(g) microstructure analysis of alloys in the longitudinal position after vacuum electromagnetic directional solidification
图 3 Ti-Si二元合金相图[14]和原始Ti-56%Si合金的析晶路径
Figure 3. Ti–Si binary alloy phase diagram and precipitation path of the Ti-56%Si alloy
图 4 (a)电磁力促进凝固晶体分离的机制，(b)电磁定向凝固分离与提纯Ti-Si合金的全过程图解
Figure 4. (a) Mechanism of electromagnetic force promoting the separation of solidified crystals, (b) and (c) illustration of the whole process of electromagnetic directional solidification separation and purification of Ti-Si alloy
图 5 (a)Ti-Si合金试样被切成五等份进行ICP-OES分析；(b)Ti-Si合金试样从底部到顶部的杂质分布
Figure 5. (a) ICP-OES analysis of the Ti–Si alloy cut into five equal parts, (b) impurity distributions of the Ti–Si alloy from the bottom to the top
图 6 Ti、Si、Fe、Mn、Ca、Mg和Al元素在不同温度下的蒸气压
Figure 6. Vapor pressures of Ti, Si, Fe, Mn, Ca, Mg, and Al elements at different temperatures
图 7 真空电磁定向凝固制备高纯TiSi2和共晶Si-Ti合金技术流程
Figure 7. New green process for the preparation of high-purity TiSi2 and eutectic Si-Ti alloys by vacuum electromagnetic directional solidification
表 1 低纯Ti-Si合金中的主要杂质及其含量
Table 1. Main impurities and their contents of the low purity Ti-Si alloys
% Fe Mn Ca Mg Al 2.43 0.81 0.18 0.21 0.13 
下载: 导出CSV
-
[1] Melsheimer S, Fietzek M, Kolarik V, et al. Oxidation of the intermetallics MoSi2 and TiSi2—A comparison[J]. Oxidation of Metals, 1997,47:139−203. doi: 10.1007/BF01682375 [2] Frommeyer G, Rosenkranz R. Structures and properties of the refractory silicides Ti5Si3 and TiSi2 and Ti-Si-(Al) eutectic alloys[J]. Metallic Materials with High Structural Efficiency, 2004,146:287−308. [3] Ting C Y, Heurle F M, Iyer S S, et al. High temperature process limitation on TiSi2[J]. Journal of the Electrochemical Society, 1986,133(12):2621−2625. doi: 10.1149/1.2108491 [4] Milanese C, Buscaglia V, Maglia F, et al. Reactive growth of niobium silicides in bulk diffusion couples[J]. Acta Mater, 2013,51:4837−4846. [5] Wen Q, Zhong Z, Yang A, et al. Effect of adding of SiC particulate on the microstructure and shear strength of SiC ceramic joint brazed with Si-24Ti alloy[J]. Journal of Adhesion Science & Technology, 2018: 1−13. [6] Zhou S, Liu X, Wang D. Si/TiSi2 heteronanostructures as high-capacity anode material for Li ion batteries[J]. Nano Letter, 2010,10(3):860−863. doi: 10.1021/nl903345f [7] Trambukis J, Munir Z A. Effect of particle dispersion on the mechanism of combustion synthesis of titanium silicide[J]. Journal of the American Ceramic Society, 2010, 73: 1240−1245. [8] Agarwal S, Cotts E J, Zarembo S, et al. The heat capacities of titanium silicides Ti5Si3, TiSi and TiSi2[J]. Journal of Alloys and Compounds, 2001,314(1-2):100−102. [9] Lee Y, Lee S. Phase formation during mechanical alloying in the Ti–Si system[J], Materials Science and Engineering: A, 2007, 449: 1099–1101. [10] Fouad O A, Yamazato M, Hiroshi A, et al. Formation of titanium silicide thin films on Si (100) substrate by RF plasma CVD[J]. Surface and Coatings Technology, 2003,169:632−635. [11] Yu W, Xue Y, Mei J, et al. Segregation and removal of transition metal impurities during the directional solidification refining of silicon with Al-Si solvent[J]. Journal of Alloys and Compounds, 2019,805:198−204. doi: 10.1016/j.jallcom.2019.07.089 [12] Ma X D, Yoshikawa T, Morita K. Si growth by directional solidification of Si-Sn alloys to produce solar-grade Si[J]. Journal of Crystal Growth, 2013,377:192−196. doi: 10.1016/j.jcrysgro.2013.05.024 [13] Koyama T, Ike D M, Shibuta Y. Silicon crystal pulling from the melt of Si-45mass%Ni alloy[J]. ISIJ International, 2008,94:496−501. [14] Massalski T B. Binary alloy phase diagrams[M]. Ohio: 2nd edition, ASM International, Metals Park, 1990. [15] 张亚坤. 工业废料再生制备Ti5Si3、TiSi2和低铁Al-Si合金的研究[D]. 昆明: 昆明理工大学. 2023.Zhang Yakun. Study on the preparation of Ti5Si3, TiSi2, and low-Fe Al-Si alloys by regeneration of industrial wastes [D]. Kunning: Kunming University of Science and Technology. 2023. [16] Kubaschewski O, Alcock C B. Metallurgical thermochemistry [M]. Oxford: Pergamon Press, 1979. -
点击查看大图
计量
- 文章访问数: 72
- HTML全文浏览量: 14
- PDF下载量: 7
- 被引次数: 0
