The effects and roles of CaCO3 and CaO in the carbothermic formation of h-BN

2012-10-01
Ozkenter, Ali Arda
ÇAMURLU, HASAN ERDEM
Sevinç, Naci
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 N-2 gas at 1500 degrees 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 N-2 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 N-2, results in more BN formation in CaCO3-added and CaO-added B2O3-activated C mixtures subjected to N-2. BN particles were also found to grow in carbon-free CaO-B2O3 melts not only in the presence of N-2 when additional BN forms but also in the absence of N-2 (under Ar) when no additional BN forms.

Citation Formats
A. A. Ozkenter, H. E. ÇAMURLU, and N. Sevinç, “The effects and roles of CaCO3 and CaO in the carbothermic formation of h-BN,” JOURNAL OF CERAMIC PROCESSING RESEARCH, vol. 13, no. 5, pp. 533–540, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/55726.