Novel Low CTE Composite Materials for Propulsion Applications

Advanced Ceramics Research, Inc. (ACR) proposes to develop novel composite systems for thermal management in propulsion applications. Traditionally, phenolic-based materials are used as insulators because of their low thermal conductivity and low cost.Unfortunately, insulating nozzle and thruster liners composed of these materials suffer from short lifetimes as a result of pyrolysis at elevated temperatures. This results in the generation of volitiles and concomittant bloating and warping of theinsulating liner. In addition, strength and CTE vary considerably as a function of temperature, presence or absence of moisture and the heating rate to which the insulator is subjected. Ceramic based liners as are highly desired because of their lowCTE's, thermal conductivities, and high melting points but they suffer from low toughness and poor thermal shock resistance. Advanced Ceramics Research Inc. proposes to fabricate a new generation of tough, high-threshold-strength and thermal shockresistant ceramic composites based on its patented Fibrous Monolith processing technology. The composites will be based on low CTE and low thermal conductivity ceramics such as sodium zirconium phosphate (NZP) and aluminum titanate.In the aerospaceindustry, damage tolerant, thermal shock resistant composites are required for thermal management and thermal protection systems for critical propulsion components. In addition, these composites are expected to have applications in the electronics andcomputer industries where low cost electrical and thermal insulators are also desired.