Castable Inorganic Composite Potting Material for High-Temperature Electromagnets

HiFundarsquo;s new low-cost, castable inorganic composite potting material (CICPM) and process proposal is in response to NASArsquo;s request for proposals that address improved materials or fabrication processes to reduce the total life cycle cost of electric propulsion thrusters.nbsp; NASA has specifically encouraged prospective proposers in fields outside of electric propulsion, like HiFunda, to apply if they have experiences with materials and processes that may be suitable for this application. nbsp;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 geopolymer composite potting material and casting process that 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 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 the large difference in coefficient of thermal expansion (CTE) of the constituent materials.nbsp; The proposed technology will mitigate this issue by adding reinforcing fibers to the potting compound and more closely matching the effective CTE of the geopolymer matrix. In Phase I, HiFunda will develop and demonstrate robustness and suitability of a CICPM in a potting test vehicle (PTV) and a subscale proof-of-concept high-temperature electromagnet (POC-HTEM) simulant. The proposed technology will be further refined and demonstrated on a high-temperature electromagnet design of interest to NASA and/or aerospace contractors in Phase II.