Characteristics of chemical vapour deposition in micro pore structure in char layer of polymer composites

Abstract The deposition of hydrocarbon pyrolysis gas in the pore structure of the char layer of polymer composites is a special chemical vapour deposition process. While investigation of hydrocarbon pyrolysis gas deposition characteristics is highly significant for obtaining an in-depth understanding of the ablation mechanism of polymer composites and the establishment of accurate ablation models, no studies on this topic have been reported to date. In this study, the deposition characteristics in the pore structure of the char layer were examined using an experimental device designed to simulate pyrolysis gas deposition in the char layer during ablation. The experimental results show that the deposition rate is affected by the change in the pore structure during the deposition process. The deposition process can be divided into rapid deposition in the pore structure, transition deposition and slow deposition on the surface of the char layer. In the temperature range of 800–1000 °C , the deposition rate in the pore structure of the char layer is significant affected by the temperature, showing an obvious linear growth relationship.