High Temperature, Low Dielectric Constant Ceramic Fibers for Missile Applications

The technology that has sustained tactical missile radomes and other electromagnetic windows is being outpaced by the increasingly challenging thermal, environmental and structural demands of hypersonic flights. New engineered materials, that exceed state-of-the-art capabilities are required to support the next generation of hypersonic vehicles. Silicon nitride is the next-generation material candidate. However, silicon nitride is a ceramic material. As such, it is a strong yet brittle material that can fail catastrophically.  The prevention of catastrophic failure necessarily relies on Ceramic Matrix Composite (CMC) technology, an engineered material consisting of fiber reinforcements embedded within a ceramic matrix, in this instance, silicon nitride fibers. This proposal addresses a void in the market: There are no commercially available silicon nitride fibers, and for good reasons. How does one make fibers with a material that does not melt, does not soften, and does not tolerate the presence of impurities at high temperatures? Free Form Fibers does it with lasers. Our proprietary fiber laser printing technology has been used to produce like materials, such a silicon carbide. Under the proposed project, Free Form Fibers will seek to adapt its fiber laser printing technology to the fabrication of fabrication of silicon nitride fibers. Once this goal is reached, Free Form Fibers will move toward establishing a domestic fiber production capacity. In parallel, Free Form Fibers will seek to establish a prototype production demonstration for silicon nitride CMC components.