Chemical Vapor Composite (CVC) Materials for Divert and Attitude Control Systems (DACS)

A study of the application of the CVC process to DACS thruster nozzle fabrication is proposed. CVC offers the benefits of conventional chemical vapor deposition (CVD) in terms of high material purity and related high temperature performance, but does so without the high residual stress associated with CVD. The CVC process also allows net shape deposition of items of complex geometry, thus reducing the costs of machining hard ceramics. Trex CVC SiC has exhibited superior high temperature properties relative to SiC components manufactured via other methods. The proposed Phase I study therefore focuses on: 1) the development of reactor fixtures for net shape deposition of SM3 DACS nozzles composed of CVC SiC; 2) the fabrication of prototype CVC SiC nozzle structures, and 3) the analysis of the material quality of the deposited component. A fourth task will be a design study on the modification of our reactors to produce CVC TaC and W components. The potential benefits of this study include: 1) DACS components with greatly reduced material erosion, and therefore improved operational projectile range and accuracy, and 2) a knowledge base for the extension of net shape CVC deposition to ultra high temperature ceramics for aluminized propellant applications.