A NANO SIC-SINOXIDATION PROTECTIVE COATING PREPARED BY ELECTROPHORETC DEPOSITION AND DIRECT NITRDATION

In this study, EPD, as a simple and low cost method, was used to coat the graphite substrate with a nano-sized SiC-Si oxidation protective coating with the ratio of 1:1. Different organic solvents used as suspension media in pre-experiments and finally Ethanol as the media, 1.4 g L of iodine as the additive, and coating parameters of 180s and 40 V for time and voltage respectively, were applied. Analysis of the kinetics of deposition revealed a linear behavior which changed as the coating thickened. In order to increase the strength of the coating and formation of SiN, direct nitridation was performed at 1400 and 1450 °C. The latter was found to be more appropriate. Microstructural analysis and recognition of phases were performed using SEM and XRDrespectively.