A review on oxidation kinetics of carbon fiber/carbon matrix composites at high temperature.

Abstract

SynopsisThe papers on the oxidation kinetics are reviewed to clarify the rate-controlling steps and the micromechanisms of oxidative attack. In the first part of the report, the general oxidation behavior of c/c composites is presented and then the detailed discussion is given on the relation of the oxidation rate to total surface area, to gas flow rate, to partial pressure of oxidizing gases and to the mechanical stresses. Finally, the oxidation rate of c/c composites with antioxidation treatments is discussed.

Characterization and Oxidation Behavior of Rayon-Derived Carbon Fibers

“…6. This is the type of Arrhenius behavior is expected for carbon and carbon fibers [7][8][9][10]14]. The kinetics at low temperatures (T \ 800°C) show a strong temperature dependence, whereas the kinetics at high temperatures (T [ 800°C) show a weak temperature dependence.…”

“…The oxidation of carbon in various forms has been extensively studied [7][8][9][10][11][12][13][14]. In general oxidation of carbon occurs in the following steps:…”

“…This is characterized by a weak temperature dependence and uniform attack of the carbon. This transition from reaction-control to diffusion-control is a critical feature of carbon oxidation and has been discussed by a number of investigators [7][8][9][10]. However it has not been measured under laboratory conditions for the rayon-derived fibers in RCC.…”

Analytical modeling of the transient ablation of a 3D C/C composite

“…Combining this expression with equations (11)(12)(13)(14), one obtains the normalized effective reactivity of the yarn as a function of the normalized height…”

“…The growth of h f as a function of time is given by the difference between the vertical recession velocities of fibers (v f ) and weak phase (v wp ): Substituting equations (11)(12) in equation (20) and rewriting the latter in dimensionless form, one obtains the following differential equation for h f (t)…”