The fusion welds of dissimilar refractory metals suffer from many limitations including shrinkage cavities, solidification cracking, embrittlement due to impurities, inferior strength and ductility, increased fabrication cost etc. GenNext Materials and Technologies, LLC proposes to develop dissimilar refractory metal friction welds for fabricating hollow cathodes free from these limitations. To achieve the improved weld performance, life time, manufacturing reliability and cost savings, the proposed joining technique, viz., friction welding, has inherent advantages over the state-of-the-art joining methods, including: The hollow cathode structural dissimilar refractory materials can be joined readily and reliably The absence of melting and solidification eliminates cavities, cracking and embrittlement in the friction welds The mechanical alloying of the dissimilar metals leads to solid solution formation eliminating brittle phases and improvement in weld reliability The friction welding process enables lowering the hollow cathode manufacturing cost due to superior performance and prolonged life of welds, short weld cycles and simple joint preparations Potential NASA Applications (Limit 1500 characters, approximately 150 words) The NASA applications for reliable, readily manufacturable, better performing hollow cathodes are very far-reaching for electric propulsion systems for space application. The proposed efforts have the potential to reduce production cost for existing thrusters and new thrusters, growing terrestrial applications, welding in space, spacecraft charge control components used for the international space station etc. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) Hollow cathodes can find commercial market opportunities including surface modification technologies such as nitriding, coating processes, elemental analysis equipment such as spectrometers etc. The dissimilar metal welding technology market opportunities, especially involving high temperature materials, are plenty in industries such as thermal power plants, nuclear power plants etc.
