Reactive Chemical Vapour Deposition of titanium carbide from H_2-TiCl_4 gas mixture on pyrocarbon: A comprehensive study

摘要

In Reactive Chemical Vapour Deposition (RCVD), the absence of orie element of the deposited carbide in the initial gas phase involves the consumption/conversion of the solid substrate. In this way, the growth of a continuous carbide layer on the substrate requires solid-phase diffusion of the reagent. In this work, a parametric study of the RCVD of titanium carbide from pyrocarbon (PyC) and an H_2-TiCl_4 mixture has been carried out. Conversion ratio, PyC consumption and carbide layer growth kinetics have been determined at lOOO°C. The influence of the H_2/TiCl_4 dilution ratio has been also investigated. The apparent inter-diffusion coefficient of the carbon through the TiC deposited layer and the direct apparent reaction rate were determined from a comparison between simulations based on a Deal-Grove-type model and the experimental results. The study has been completed with FTIR spectrometry analyses of the gases.