Innovative Tungsten Alloys for Advanced Propulsion Systems

Non-conventional technologies are needed to revolutionize space propulsion. Development of materials with improved properties is essential to increase performance and reduce cost. Advancements are needed for components in high powered electrical, beamed energy, and nuclear propulsion systems. Innovative Vacuum Plasma Spray (VPS) processes for fabricating net shape, tungsten-rhenium-hafnium carbide alloy components are proposed. Tungsten is being used for its high melting temperature and chemical stability. However, conventional tungsten materials have to be forged to get adequate properties. Forging tungsten into complex shapes is difficult and has limited its application. Tungsten alloys yield improved properties as compared to conventional unalloyed tungsten. It is well documented that small additions of rhenium improve the ductility of tungsten without significantly decreasing the melting point. Also, dispersion hardening by additions of HfC increases the high temperature strength by pinning grain boundaries. In Phase I, W-Re-HfC powders and process parameters will be developed to fabricate samples for characterization and hoop tensile testing. After optimization, nozzles will be fabricated and hot fire tested at ATK-Thiokol. Development of these materials will allow the production of components with unique properties and reduce the size, weight, and cost of propulsion systems.