Carbothermic formation of boron nitride

Date

2003-01-01

Author

Aydogdu, A
Sevinc, N

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

222
views

0
downloads

Formation of boron nitride by reaction of boric oxide with carbon and nitrogen was studied. It was found from the results of experiments conducted by holding BA-activated C mixtures under a flowing nitrogen atmosphere that formation of boron nitride was complete in 120 min at 1500 degreesC. After cleaning the reaction product from the ash of the activated carbon and from the unreacted B2O3 pure BN powder was obtained. B4C was found to exist as an intermediate species in the reaction products of the experiments in which BN formation was not complete. The results of experiments conducted with the objective of gaining an insight into the reaction mechanism by using different geometrical arrangements show that liquid 13,03 and solid carbon need not be in contact in the formation of BN from B2O3, C and N-2 and indicate that the reaction proceeds through a gaseous boron containing species which is most probably B2O3(g)

Subject Keywords

Materials Chemistry, Ceramics and Composites

URI

https://hdl.handle.net/11511/64832

Journal

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY

DOI

https://doi.org/10.1016/s0955-2219(03)00092-x

Collections

Department of Metallurgical and Materials Engineering, Article

Suggestions

OpenMETU
Core

Effect of calcium carbonate addition on carbothermic formation of hexagonal boron nitride ÇAMURLU, HASAN ERDEM; SEVİNÇ, NACİ; Topkaya, Yavuz Ali (Elsevier BV, 2008-01-01) Effect of CaCO3 on formation of hexagonal boron nitride (h-BN) was investigated by holding CaCO3 free and CaCO3 added activated carbon-boric oxide mixtures under nitrogen atmosphere at 1500 degrees C for 30-120 min. Amount of CaCO3 addition was varied in the range of 0-50 wt.% of the initial mixture. Products were characterized by powder X-ray diffractometry, FT-IR analysis, quantitative chemical analysis, scanning electron microscopy and BET specific surface area analysis. It was observed that calcium carb...
Activity-corn position relations in MuCr(2)O(4)-CoCr2O4 solid solutions and stabilities of MnCr2O4 and CoCr2O4 at 1300 degrees C Koc, N; Timucin, M (Wiley, 2005-09-01) Phase equilibria in the system MnO-CoO-Cr2O3 were investigated at 1300 degrees C under controlled oxygen partial pressures by using the gas equilibration technique. The CoO activities in various phase assemblages of the system were measured by determining the partial pressures of oxygen in the gas phase for coexistence with metallic cobalt. The activity data revealed that at 1300 degrees C, MnO-CoO and MnCr2O4-CoCr2O4 solid solutions exhibit mild positive departures from ideal behavior. The activities in th...
Kinetic model for alpha-tricalcium phosphate hydrolysis Durucan, Caner (Wiley, 2002-08-01) A mechanistic model for the kinetics of hydrolysis of alpha-tricalcium phosphate (alpha-Ca-3(PO4)(2) or alpha-TCP) to hydroxyapatite (Ca10-x(HPO4)(x)(PO4)(6-x)(OH)(2-x) or HAp) has been developed. The model is based on experimental hydrolysis rate data obtained using isothermal calorimetry. Analysis of the kinetic data according to the general kinetics models in terms of the fractional degree of reaction and time suggests the hydrolysis to be controlled by different rate-limiting mechanisms as reaction proc...
Combustion synthesis of calcium phosphate bioceramic powders Tas, AC (Elsevier BV, 2000-12-01) Calcium phosphate (hydroxyapatite and tri-calcium phosphate) bioceramics closely resembling, in chemical composition, those found in vivo in human bones have been synthesized by using novel synthetic body fluid solutions via the self-propagating combustion synthesis (SPCS) method. Powder characterization was performed by XRD: ICP-AES, FTIR and SEM.
Stereoregular polymerization of methylmethacrylate by atom transfer radical polymerization Aran, B; Usanmaz, Ali (Informa UK Limited, 2006-01-01) Methyl methacrylate (MMA) was polymerized by the atom transfer radical polymerization (ATRP) method to obtain living low molecular weight polymers. The initiator was p-toluenesulfonylchloride and the catalyst ligand complex system was CuCl-4,4'dimethyl 2,2'bipyridine. Polymers with controlled molecular weight were obtained. The polymer chains were shown by NMR spectrum to be mostly syndiotactic. The molecular weight distributions were measured by the GPC method. The K and a constants in [eta] = KM alpha equ...

Citation Formats

A. Aydogdu and N. Sevinc, “Carbothermic formation of boron nitride,” JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, pp. 3153–3161, 2003, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/64832.