High-Strength Carbide-Based Materials for Solid Rocket Nozzles

Hi-Z Technology, Inc. (Hi-Z) proposes to develop improved tantalum carbide sheet materials that can be laminated with graphite sheets for a zero erosion throat for aluminized propellant rocket motors. The tantalum carbide sheet will have a uniform composition in the range TaC0.7 to TaC0.89 to take advantage of the higher melting point, lower elastic modulus and lower ductile-brittle transition temperature compared with stoichiometric TaC. The sheet will be processed to leave residual compression stresses in the surface. The laminate material will be capable of withstanding up to 0.5% strain due to thermal shock. The technology developed uses low cost, commercially available sheet as a precursor and can be applied to advanced compositions to operate at 6600°F or higher. Some work will be done on hot pressed material to provide a baseline for comparison with earlier work and will include Augier spectroscopy.