The effects of different molten salt composition on morphology and purity of ZrB2 powder obtained via direct molten salt reaction method

Subject Areas : Ceramics

mohammad velashjerdi ¹ , Hossien sarpoolaky ² , Alireza Mirhabibi ³

1 - School of Metallurgy and Materials Engineering, Iran University of Science and Technology,Tehran,Iran.
2 - School of Metallurgy and Materials Engineering, Iran University of Science and Technology,Tehran,Iran.
3 - School of Metallurgy and Materials Engineering, Iran University of Science and Technology,Tehran,Iran.

Received: 2015-05-25 Accepted : 2015-07-12 Published : 2015-09-01

Keywords: Zirconium Diboride, Molten Salt, reaction, Low temperature, Composition,

Abstract :

Zirconium Diboride (ZrB2) powder was synthesized at low temperature via a Direct Molten Salt Reaction (DMSR) method. The influence of different salt compositions including eutectic mixture of (KF-NaF), (KF-KCl) and (KCl-NaCl) on the morphology and purity of the reaction products was studied. The obtained samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Furthermore, the formation mechanism of ZrB2 was investigated by DTA/TG. The results show that alongside eutectic mixture of chloride salt, ZrB2 powder can be obtained with eutectic mixture of fluoride salt. In addition, obtained ZrB2 powder without additional salt has hexagonal prism morphology, whereas ZrB2 particles prepared with eutectic mixture of fluoride salt have higher purity and particle size and hexagonal morphology as well. Synthesized ZrB2 Powder in chlorofluoride salt has lower particle size and purity and non-uniform morphology. Synthesized ZrB2 powder is different from starting material in term of morphology and particle size therefore the dissolution–precipitation mechanism may play a dominant role on the synthesis of ZrB2 during DMSR process.

References:

1. W. G. Fahrenholtz, G. E. Hilmas, I. G. Talmy and J. A. Zaykoski, Refractory Diborides of Zirconium and Hafnium, J. Am. Ceram. Soc, Vol. 90, 2007, pp. 1347–1364.


2. B. Post, F. W. Glaser and D. Moskowitz, Structural Transition Metal Diborides, Acta. Metal., Vol. 2, 1954, pp. 20-25.


3. J. K. Sonber, A. K. Suri, Synthesis and Consolidation of Zirconium Diboride : review, Adv. App. Ceram, Vol. 110, 2011, pp. 321–334.


4. M. Jalaly, M. Tamizifar, M. S. Bafghi and F. J. Gotor, Mechanochemical synthesis of ZrB₂-SiC-ZrC nanocomposite powder by metallothermic reduction of zircon, J. Alloys Compd., Vol. 581, 2013, pp. 782–787.


5. S. Motojima, K. Funahashi and K. Kurosawa, ZrB₂ coated on copper plate by chemical vapour deposition and its corrosion and oxidation stabilities, Thin Solid Films, Vol. 189, 1990, pp. 73–79.


6. B. Yang, J. Li, B. Zhao, Y. Hu, T. Wang, D. Sun, R. Li, S. Yin, Z. Feng, Q. Tang and T. Sato, Synthesis of hexagonal-prism-like ZrB₂ by a sol – gel route, Powder Technol, Vol. 256, 2014, pp. 522–528.


7. S. E. Kravchenko, V. I. Torbov and S. P. Shilkin, Nanosized zirconium diboride: Synthesis and properties, Russ. J. Inorg. Chem., Vol. 56, 2011. pp. 506–509.


8. T. Y. Kosolapova, T. I. Serebryakova, I. Popova and V. I. Babich, Impurities in ZrB2 Prepared by Different Methods, J. Less. Com. Metal, Vol. 7, 1979, pp. 303–307.


9. P. Afanasiev, C. Geantet and C. Geantet, Synthesis of Solid Materials in Molten Nitrates, Cord. Chem. Rev, Vol. 180, 1998, pp. 1725–1752.


10. 10. B. Roy, S. P. Ahrenkiel and P. A. Fuierer, Controlling the Size and Morphology of TiO2 Powder by Molten and Solid Salt Synthesis, J. Am. Ceram. Soc, Vol. 91, 2008, pp. 2455–2463.


11. 11. S. Zhang, M. Khangkhamano, H. Zhang and H. A. Yeprem, Novel Synthesis of ZrB₂ Powder via Molten – Salt - Mediated Magnesiothermic Reduction, J. Am. Ceram. Soc, Vol. 97, 2014, pp. 1686–1688.


12. 12. M. velashjerdi, H. sarpoolaky and A. R. Mirhabibi, Novel synthesis of ZrB₂ powder by low temperature direct molten salt reaction, Ceram. Iner, Accepted manuscript.


13. 13. Y. Zhao, S. Zhang, G. Chen, and X. Cheng, Effects of Molten Temperature on the Morphologies of  in Situ Al3Zr and ZrB2 Particles and Wear Properties of (Al₃Zr + Zrb₂)/Al Composites, Mater. Sci. Eng. A, Vol. 457, 2007, pp. 156–161.


14. 14. X. B. Degang Zhao, Xiangfa Liu, Yuxian Liu, In-Situ Preparation of Al Matrix Composites Reinforced by TiB2 Particles and Sub-Micron ZrB ₂, J. Mater. Sci, Vol. 40, 2005, pp. 4365–4368.


15. 15. H. J. Yang, Y. T. Zhao, G. Chen, S. L. Zhang, and D. Bin Chen, Preparation and Microstructure of In-Situ (ZrB₂+Al₂O₃+Al₃Zr) P/A356 Composite Synthesized by Melt Direct Reaction, Trans. Nonferr. Met. Soc. Vol. 22, 2012, pp. 571–576.


16. 16. Lide DR, Haynes WMM. CRC hand book of chemistry and physics, Boca Raton, CRC Press, 2010.


17. 17. S. H. Lee, Y. Sakka, and Y. Kagawa, Corrosion of ZrB₂ Powder During Wet Processing - Analysis and Control, J. Am. Ceram. Soc, Vol. 91, 2008, pp. 1715–1717.


18. 18. Z. Rui, Y. T. Zhao, S. L. Zhang, and Z. H. Jia, In Situ Fabrication and Microstucture of ZrB₂ Particles Reinforced Aluminum Matrix Composites, Adv. Mater. Res, Vol. 476, 2012, pp. 122–125.


19. 19. L. Jiao, Z. Zhang, H. Shang, and Y. Gao, The Magnetic Chemical Preparation and Properties of the Al3Zr /A602 Aluminum Matrix Composites, Proc. 2nd International Conference on Electronic & Mechanical Engineering and Information Technology, China, 2012, pp. 1522.


20. 20. ACerS-NIST Phase Equilibria Diagrams Database, Ver 3. 1. 2005.


21. 21. Y. Birol, Production of Al-B alloy by heating Al/KBF4 powder blends, J. Alloys Compd, Vol. 481, 2009, pp. 195–198.


22. 22. D. k. Nguyen and V. Danek, Viscosity of the Molten System KF - KCl - K₂TiF₆, Chem. Papers, Vol. 50, 1995, pp. 4–7.


23. 23. R. E. Thoma and W. R. Grimes, Phase Equilibrium Diagrams for Fused Salt Systems, Oak ridge national. 1957.


24. 24. G. J. Janz, Molten Salt Hand Book, Academic Press, New York, 1967.


25. 25. V. Danek, Physico-Chemical Properties of Molten Salt Electrolytes, Elsevier, London, 1992.