Castable Inorganic Composite Potting Material for High-Temperature Electromagnets

This Phase II proposal is being submitted after the successful completion of HiFundarsquo;s Phase I SBIR project which was responsive to NASArsquo;s request for proposals that address improved materials or fabrication processes to reduce the total life cycle cost of electric propulsion thrusters. Insulation and potting degradation during thruster operations can lead to early thruster failures that have occurred with existing processes for manufacturing and potting magnetic wire. HiFunda is proposing a new filament winding in situ potting (FWISP) process that utilizes a castable inorganic composite potting material (CICPM) coupled with conventional or accelerated hot press curing. The proposed FWISP process will extend the temperature limits of conventional polymeric and/or ceramic potting materials thereby minimizing or eliminating instances of potting and insulation failures. High-temperature electromagnet (HTEM) coils are potted with a ceramic material that is intended to fill the gaps between the windings and to be free of voids. Unfortunately, in practice, the ceramic potting compound develops cracks due to the large startup thermal gradients and differences in coefficient of thermal expansion (CTE) of the constituent materials.nbsp; The proposed technology will improve the robustness by minimizing porosity and adding reinforcing fibers to the CICPM. Phase II efforts will build upon the Phase I results and will develop and demonstrate small and large prototype Phase II HTEM voice-of-customer (VOC) designs of interest to NASA and/or potential commercial end users. In Phase II, HiFunda will optimize the FWISP and CICPM processes for production of small and large technology demonstration prototype HTEMs that will be tested, characterized, and provided to NASA for evaluation. The proposed technology will be further refined and demonstrated in a Phase 2-E/X on a HTEM designs of interest to customers in the commercial space and other industrial sectors.