Silicon carbide (SiC) is the generic name for a material which is produced and fabricated by a number of processing routes. One of the three SiC materials investigated at NCSU is Norton Company's NC-430, which is produced by reaction-bonding of Si vapor with a porous SiC host which also contains free C. The Si combines with the free C to form additional SiC and a second phase of free Si. Chemical vapor deposition (CVD) of CH3SiCI3 onto a graphite substrate was employed to produce the second SiC investigated. This process yielded a theoretically dense polycrystalline material with highly oriented grains. The third SiC was a pressureless sintered material (SOHIO Hexoloy) which contains B and excess C as sintering additives. These materials are candidates for applications such as components for gas turbine, adiabatic diesel and sterling engines, recouperators and heat exchangers.
