This Small Business Innovation Research Phase I project will produce silicon carbide fibers that can be used as reinforcements to toughen ceramics for use at high temperatures.There are underlying sound technical and economic reasons why the presently available fibers have not made headway commercially. These fibers degrade both chemically and mechanically during manufacture of the ceramic matrix composite. The cost of these fibers can range from $500 to $1,000 per kg. depending upon the quality of the fiber and the quantity ordered. This high cost prohibits technical development of much needed ceramic matrix composites in a major way. The requirements for low-cost silicon carbide fiber manufacture by the procedures disclosed are rather simple: 1) low-cost silicon and carbon containing raw materials, 2) simple furnacing technique that involves self-heating of the charge, and 3) complete avoidance of fiber spinning or drawing and sintering methodology or polymer chemical conversion technology and chemical vapor deposition (CVD) methods. The proposed process addresses all of the above aspects. They include: 1) Potentially low-cost production relative to existing technology due to the use of readily available, low-cost raw materials and novel furnacing technique involving relatively low technology that can be practiced world-wide, 2) potentially single-phase alpha or beta silicon carbide fiber that will withstand high temperature (> 1400 oC) use, and 3) relatively low risk in scale-up to large volume production methods. The silicon carbide fibers resulting from this research can form ceramic composites used in heat exchangers and chemical reactors which are subject to high-temperature, high-pressure, and highly corrosive environments. These fibers can also be used in ceramic composites for waste heat recovery air pre-heaters in aluminum re-melt facilities, ceramic radiant tubes in aluminum melting furnaces, and applications in high-temperature incineration of municipal and industrial waste systems. Other applications include hazardous and toxic waste containment vessels made of ceramic composites and high temperature ceramic filters.
