Development and qualification of a rayon carbon fabric for ablative materials

Abstract

In 1996, it was decided by Snecma Moteurs to launch a replacement program of NARC rayon, which was the precursor of our standard rayon fabric. This rayon fabric, carbonized in France into carbon fabric (dubbed Cl), was currently used as basic reinforcement of carbon/ phenolic prepregs. These prepregs are used for the production of ablative or insulator materials in Solid Rocket Motors, such as the nozzle of Ariane 5 strapon boosters. For several years, Snecma Moteurs performed basic research studies in order to develop a new carbon fabric allowing replacing NARC rayon based phenolic materials without design and/or functional modification of the existing nozzles. Snecma Moteurs has designed, developed and qualified a new rayon-based carbon fabric (dubbed C2), carbonized in a continuous process flow. As this C2 fabric is mainly used for Ariane 5 booster nozzles, the production rate is 11 tons/year (24000 Ibs/year) since January 2000, thanks to a dedicated manufacturing facility settled at Snecma Moteurs plant located at Le Haillan, near Bordeaux, in France. In order to increase the long-term availability of the delivery source of the C2 fabric, the process is based on a tire cord rayon fiber hopefully allowing cost savings. Two different rayon sources were evaluated and qualified. C2 carbon fabric can be processed using standard methods similar to those used with Cl fabric: phenolic resin impregnation, tape wrapping and autoclave curing. The equivalence between Cl based and C2 based phenolic materials has been demonstrated through a material qualification program including a detailed and complete characterization (fabric, prepreg, composite). The qualification program included 4 SRM static firing tests. The last one, in May 2000, was the static test of an Ariane 5 strap-on booster (237 metric tons of propellant). AIAA member 2 Copyright© 2001 by Snecma Moteurs. Published by the American Institute of Aeronautics and Astronautics, Inc with permission. -2American Institute of Aeronautics and Astronautics (c)2001 American Institute of Aeronautics & Astronautics or Published with Permission of Author(s) and/or Author(s)' Sponsoring Organization. This paper gives the main characterization data concerning C2, Carbon/phenolic composite and the results of static tests. All the information gathered through the development and the qualification programs show a similar behavior of the components made of Cl or C2 fabric. Snecma Moteurs has succeeded in his NARC replacement program and has already introduced C2 fabric in the production of Ariane 5 strap-on booster