Kinetic investigation of chemical vapor deposition of B4C on tungsten substrate

Date

2006-12-01

Author

Karaman, Mustafa
Sezgi, Naime Aslı
Doğu, Timur
Ozbelge, H. Onder

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Production of beta-rhombohedral boron carbide (B4C) on a tungsten substrate by the chemical vapor deposition from a BCl3-H-2-CH4 gas mixture was achieved. An impinging-jet reactor was used to minimize the mass-transfer limitations on the reaction kinetics, which made a detailed kinetic investigation possible. Results of the XRD and XPS analyses showed that the solid product formed on the substrate is a rhombohedral B4C phase. Both dichloroborane and boron carbide formation rates were found to increase with an increase in the inlet molar fraction of BCl3. The formation rate of boron carbide increased with an increase in the inlet molar fraction of CH4. However, no effect on the formation rate of dichloroborane was observed with an increase in the inlet molar fraction of methane. The activation energy of the boron carbide formation reaction was ascertained to be 56.1 +/- 4.0 kJ/mol. The boron carbide formation reaction was proportional with the 0.34 +/- 0.055 power of the initial boron trichloride concentration and 0.64 +/- 0.084 power of the initial methane concentration. (c) 2006 American Institute of Chemical Engineers.

Subject Keywords

Chemical vapor deposition (CVD), Boron carbide, Refractory fibers, Hard coatings, Jet impingement

URI

https://hdl.handle.net/11511/32324

Journal

AICHE JOURNAL

DOI

https://doi.org/10.1002/aic.11017

Collections

Graduate School of Natural and Applied Sciences, Article

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Mechanism Studies on CVD of Boron Carbide from a Gas Mixture of BCl3, CH4, and H-2 in a Dual Impinging-jet Reactor Karaman, Mustafa; Sezgi, Naime Aslı; Doğu, Timur; Ozbelge, Hilmi Onder (2009-03-01) Nearly pure boron carbide free from impurities was produced on a tungsten substrate in a dual impinging-jet chemical vapor deposition reactor from a BCl3, CH4, and H-2 mixture. The Fourier Tran form Infrared (FTIR) analysis proved the formation Of reaction intermediate BHCl2, which is proposed to occur mainly in the gaseous boundary layer next to the substrate surface. Among a large number of reaction mechanisms proposed only the ones considering the molecular adsorption of boron carbide on the substrate su...
Chemical vapor deposition of boron carbide Karaman, Mustafa; Özbelge, Önder; Department of Chemical Engineering (2007) Boron carbide was produced on tungsten substrate in a dual impinging-jet CVD reactor from a gas mixture of BCl3, CH4, and H2. The experimental setup was designed to minimise the effect of mass transfer on reaction kinetics, which, together with the on-line analysis of the reactor effluent by FTIR, allowed a detailed kinetic investigation possible. The phase and morphology studies of the products were made by XPS, XRD,micro hardness and SEM methods. XPS analysis showed the existence of chemical states attrib...
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Kinetic studies for boron carbide formation in a dual impinging-jet reactor Noyan-Dilek, S; Ozbelge, HO; Sezgi, Naime Aslı; Dogu, T (2001-02-07) The chemical vapor deposition (CVD) of boron carbide was investigated on a tungsten substrate from a gas mixture of BCl3, H-2, and CH4 in a dual impinging-jet reactor that was connected to an FT-IR spectrometer for on-line analysis of the reactor effluent stream. During CVD of boron carbide, the formation of BHCl2 was experimentally verified, and beta -rhombohedral B4C was formed. Conversion to boron carbide was found to increase with an increase in the BCl3/CH4 ratio. However, conversion to dichloroborane ...
BHCl2 formation during chemical vapor deposition of boron in a dual-impinging jet reactor Sezgi, Naime Aslı; Ozbelge, HO (1997-12-01) Chemical vapor deposition (CVD) of boron from BCl3 and Hz was investigated in a dual-impinging jet reactor which was connected to an FT-IR spectrometer for on-line chemical analysis of the reactor outlet stream. Formation of the intermediate, BHCl2, during CVD of boron on a hot tungsten substrate was experimentally verified, Boron deposition started at substrate temperatures of around 750 degrees C and showed a significant deposition rate increase with an increase in temperature. At a surface temperature of...

Citation Formats

M. Karaman, N. A. Sezgi, T. Doğu, and H. O. Ozbelge, “Kinetic investigation of chemical vapor deposition of B4C on tungsten substrate,” AICHE JOURNAL, pp. 4161–4166, 2006, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32324.