The effects and roles of CaCO3 and CaO in the carbothermic formation of h-BN
1
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
The effects of CaCO3 and CaO on the carbothermic formation of h-BN were investigated by subjecting plain, CaCO3-added and CaO-added B2O3-activated C mixtures to N2 gas at 1500 ο C. Both additions were found to result in the formation of more BN with larger particle sizes in a given time. It was shown that BN forms in the absence of carbon in CaO-B2O3 melts but not in a plain B2O3 melt subjected to N2 by a mechanism involving nitrogen dissolution in and formation of BN from the melt. This mechanism, in addition to the reaction of B2O3 with C and N2, results in more BN formation in CaCO3-added and CaOadded B2O3-activated C mixtures subjected to N2. BN particles were also found to grow in carbon-free CaO-B2O3 melts not only in the presence of N2 when additional BN forms but also in the absence of N2 (under Ar) when no additional BN forms
Abstract
The effects of CaCO3 and CaO on the carbothermic formation of h-BN were investigated by subjecting plain, CaCO3-added and CaO-added B2O3-activated C mixtures to N2 gas at 1500 ο C. Both additions were found to result in the formation of more BN with larger particle sizes in a given time. It was shown that BN forms in the absence of carbon in CaO-B2O3 melts but not in a plain B2O3 melt subjected to N2 by a mechanism involving nitrogen dissolution in and formation of BN from the melt. This mechanism, in addition to the reaction of B2O3 with C and N2, results in more BN formation in CaCO3-added and CaOadded B2O3-activated C mixtures subjected to N2. BN particles were also found to grow in carbon-free CaO-B2O3 melts not only in the presence of N2 when additional BN forms but also in the absence of N2 (under Ar) when no additional BN forms
참고문헌 (21)
- P. Popper, "Special Ceramics" (1960), Heywood and Company Ltd.
- S. Rudolph, , Am. Ceram. Soc. Bull, 73, pp.89~90 (1994)
- R. Haubner, "Boron Nitrides-Properties, Synthesis and Applications" (2002), Springer-Verlag
- "The Economics of Boron" (2002), Roskill Information Services Ltd.
- R. T. Paine, , Chem. Rev, 90, pp.73~91 (1990)
- H. Zhao, , Ceram. Int, 35, pp.105~109 (2009)
- M. Hubacek, , J. Solid State Chem, 123, pp.215~222 (1996)
- A. Aydogdu, , J. Eur. Ceram. Soc, 23, pp.3153~3161 (2003)
- H. E. Çamurlu, , J. Mater. Sci, 41, pp.4921~4927 (2006)
- T. S. Bartniskaya, , J. Less Common Met, 117, pp.253~258 (1986)
- S. J. Yoon, , A. A. Jha J. Mater. Sci, 31, pp.2265~2277 (1996)
- S. N. Pikalov, , Powder Metall. Met. C+, 21, pp.404~406 (1988)
- T. S. Bartnitskaya, , Powder Metall. Met. C+, 35, pp.296~300 (1996)
- N. F. Ostrovskaya, , Powder Metall. Met. C+, 35, pp.636~639 (1996)
- H. E. Çamurlu, , J. Eur. Ceram. Soc, 28, pp.679~689 (2008)
- H. E. Çamurlu, , Ceram. Int, 35, pp.2271~2275 (2009)
- E. Martinez, , Metall. Trans, 21B, pp.97~104 (1990)
- D.J. Min, , Metall. Trans, 21B, pp.1025~1032 (1990)
- E. M. Levin, "Phase Diagrams for Ceramists" (1964), The American Ceramic Society
- B. D. Cullity, "Elements of X-Ray Diffraction" (2001), Prentice Hall
- S. V. Gurov, , Powder Metall. Met. Ceram, 24, pp.607~609 (1985)