SiC Matrix Composite Rocket Thrust Chamber with Integrated SiC Foam Propellant Diffuser/Injector

"Liquid rocket engine systems currently in development or being considered for future development will require a variety of subsystems for axial, reaction control, target intercept, and auxiliary propulsion. Recent developments in fiber-reinforced ceramicmatrix composites and porous reticulated ceramics offer promise to increase performance, manufacturability and cost over currently available refractory metal propulsion components. The objective of this Phase I program is to demonstrate the feasibility ofproducing a lightweight SiC matrix composite rocket propulsion thrust chamber incorporating a fully integrated reticulated SiC foam propellant diffuser/injector. A previously developed intraply fiber preform hybridization technique will be utilized for thechamber to mitigate process-induced matrix microcracking and gaseous permeability inherent in C/SiC composites. Optimized hybrid fiber preforms of T300 and Hi-Nicalon will be braided over geometrically contoured mandrels and densified with a SiC matrixproduced by chemical vapor infiltration (CVI). Following partial consolidation of the preform, a reticulated foam diffuser/injector element will be inserted into the forward end of the combustion chamber and CVI-SiC integrated with the composite thrustchamber during final matrix densification. Reticulated open-cell SiC foam specimens of various porosities and densities will be produced and experimentally evaluated to determine their res