High Strength Carbide-Based Fibrous Monolith Materials for Solid Rocket Nozzles

摘要

Next generation aluminized propellants have become more energetic in order to impart a higher specific impulse to the system, resulting in higher temperatures and pressures that need to be contained. Nozzles are exposed to temperatures of up to 6100 F (3371 C) during aluminized propellant burn. Additionally, these propellants produce very hostile, abrasive environments; existing materials for boost throat applications have been shown to erode at unacceptable rates, leading to a loss in performance due to throat widening. Implementation of these propellants for boost and thrust applications requires the development of a new family of materials providing structural integrity, thermal protection, and low- or near-zero ablation rates above 3000 C. Erosion resistant nozzles which can maintain dimensional stability during firing are required. Erosion in these systems can be attributed to the reactive environment, mechanical erosion, and spalling due to thermal shock. Appropriate material selection and architectural design can both be utilized to minimize erosion due to all three of these factors.