Experimental and thermodynamic investigation of SiC nanofibers formation using HSC software

The C/SiC coating containing SiC nanofibers has been developed on graphite substrate using a pack cementation technique. The HSC chemistry software package was used for thermodynamics analysis and chemical equilibrium calculations during formation of SiC coating. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis demonstrate that the coating obtained by the pack cementation is a dense structure comprising β-SiC. By energy dispersive spectroscopy (EDS) analysis, a gradient C–SiC transition layer can be characterized at the graphite-coating interfaces. The SiC nanofibers with the diameter in the range of 50-80 nm were observed on coating. The theoretical calculation results indicated that in the early stages of the process, aluminium oxide reacts with silicon and carbon. SiC particles were formed as a consequence of the reaction of silicon with carbon oxide and carbon with silicon oxide. The growth of the SiC nanofibers was attributed to the gaseous reaction of SiO with CO. The results from simulations and experiments are consistent with each other.

کلیدواژه ها:

HSC chemistry ، Thermodynamics analysis ، Silicon carbide ، Nanofibers ، Coatings