Development of Advanced CMC Materials for Dual-bell Rocket Nozzles

Abstract

The main goal of sub-project D7 is the development of advanced ceramic matrix composites (CMCs) for a dual-bell application. These CMCs are characterized by continuous carbon filaments which are embedded in a silicon carbide matrix (SiC). The process route used for the manufacture of the so called C/C-SiC material is the Liquid Silicon Infiltration (LSI), also called Melt Infiltration (MI). The CMC material is favorable to replace conventional high-density engine alloys due to their outstanding high temperature properties. In a liquid-fueled rocket engine the material must withstand extreme conditions, e.g. high gas temperatures and high mechanical loads. In a first step the specifications and requirements of a CMC nozzle material have been defined and also the thermal and mechanical loads of a typical launcher system engine (e.g.Vulcain 2-Ariane 5) were described prior to the further development of C/C-SiC. A central part of the development is the integration of the filament winding process into the LSI route and the characterization of specimens in terms of thermo-mechanical properties by variation of fibre orientation. The analysis of permeability to hot gases and a study on oxidation behavior is planned in the upcoming year. The manufacturing process and the concept of characterizing the CMC material are presented and discussed.