Effect of temperature and CH4/ZrCl4 molar ratio on ZrC layers deposited in a vertical-wall CVD system
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Date
2016
Journal Title
Journal ISSN
Volume Title
Publisher
Proceedings of SAIP
Abstract
The synthesis of ZrC layers was performed in an in-house developed,
vertical-wall chemical vapour deposition (CVD) system operating at atmospheric
pressure. Zirconium tetrachloride and methane were used as zirconium and carbon
sources respectively, with an excess of hydrogen as reducing agent. Argon was used to
carry the vaporised ZrCl4 at 300 °C to the reaction chamber. The deposition of ZrC
was carried out on graphite substrates at temperatures in the range of 1200 °C –1600
°C. The molar ratio of CH4/ZrCl4 was varied from 6.04 to 24.44. Response surface
methodology was applied to optimise the process parameters for the deposition of
ZrC. A central composite design was used to investigate the effects of temperature
and molar ratio of CH4/ZrCl4 on the average crystallite size. Quadratic statistical
models for crystallite size was established. Scanning electron microscopy (SEM)
images show that the coatings became more uniform with increased particle
agglomeration as temperature increased.
Description
Keywords
Temperature, CH4/ZrCl4 molar ratio, ZrC layers, CVD system
Citation
Biira, S., Bissett, H., Nel, J. T., Hlatshwayo, T. T., Crouse, P. L., & Malherbe, J. B. (2016). Effect of temperature and CH4/ZrCl4 molar ratio on ZrC layers deposited in a vertical-wall CVD system.