Manufacturing Method of Carbon/Phenolic Composites and its Implication on Ablative Charactristics

Carbon/phenolic composites are used in the nozzle parts of solid rocket motors due to their heat-resisting, ablation, and high strength characteristics, which are required to endure the high temperature and pressure of combustion gas passing through the nozzle. One of the most important factors on erosion rate is the void content of the ablative composites. Facilities should be designed to simplify the exhaust of volatile components, in order to reduce the void content in the manufactured samples. Accordingly, to reduce the void percentage of carbon/phenolic composites in this study, samples were manufactured by the vacuum bag molding technique and cured in an autoclave. In order to compare the effect of manufacturing process on the ablation characteristics of carbon/phenolic composites, another batch of samples was produced by the acid curing method. The specimens were exposed to plasma torch flame based on ASTM E285-80. The results showed that the void percentage of samples which was manufactured by the autoclave process was 60% lower than the acid-cured samples, and this led to reduce the linear erosion rate of these composites