Ceramic matrix composites (CMC) have a low density and retain their strength at much higher temperatures than competing alloys. At the same time, they have a damage-tolerant fracture behavior and an excellent oxidation and corrosion resistance. Thus, they are predestined for extreme environments such as in nuclear reactors, aerospace applications including jet turbines, thermal protection systems and rocket nozzles but also in metal processing. Key to the advantageous properties of CMC is the designed interaction of the fibers with the matrix as well as sophisticated processing.

In our talk we will first present recent results on fibers, which were processed from hybrid polymers based on commercial polyacrylonitrile copolymer (PAN) and oligosilazane (OSZ) precursors. The polymers were processed by electrospinning and wet spinning. The resulting non-wovens and multifibrillar fibers exhibited superior oxidation resistance and mechanical properties compared with competing carbon fibers, but they also have a much lower price than silicon carbide fibers. Most importantly, the nonwovens combined a low thermal conductivity with a high electrical conductivity, which is unique compared to other known materials. Secondly, we will present results on one of the first successful attempts for additive manufacturing of carbon fiber reinforced silicon carbide CMC. In this case carbon-fiber filled PEEK filaments were processed by fused filament fabrication with subsequent thermo-oxidative curing and liquid silicon infiltration, which reducing costly hard-machining by a large extent.