The Behavior of Pyro-Carbon Matrix Synthesized Through Isothermal Chemical Vapor Infiltration (I-CVI) Process

Abstract

Isothermal chemical vapor infiltration (I-CVI) process used for the manufacture of carbon fiber-reinforced carbon matrix (C/C) composite products is process parametric sensitive. In this work, the characteristics of the pyro-carbon (PyC) matrix deposited through the I-CVI process are investigated. The chemical kinetics of this process was simulated to study the change in microstructure of PyC with the variation of process parameter. The nature of the carbon deposited at various temperatures, pressure, residence time of gas, and the effect of the molar ratio of methane to nitrogen gas on the microstructure of the deposited (PyC) is examined. The effect of carbon fiber preform porous structure on the I-CVI process and its densification characteristics was further studied. It was observed that during the I-CVI process, pores are playing a major role in the densification characteristics. The results have revealed that the properties of I-CVI processed C/C products can be improved by proper selection and controlling of process parameters. Based on this study, process guidelines are proposed for densification of continuous carbon fiber perform to optimally develop C/C composite products.