High Performance SiC/SiC Composites for Structural Fusion Reactor Components

50680-98-I High Performance SiC/SiC Composites for Structural Fusion Reactor Components--Ceramic Composites, Inc., 1110 Benfield Blvd., , Millersville, MD 21108-3001; (410) 224-3710 Mr. Matthew Pope, Principal Investigator Mrs. Sharon S. Fehrenbacher, Business Official DOE Grant No. DE-FG02-98ER82550 Amount: $74,952 SiC(f)/SiC continuous fiber ceramic composites (CFCCs) have been identified as the material of choice in the fusion reactor environment. However, three critical problems must be solved before SiC(f)/SiC materials are widely used for structural fusion components. These problems are: (1) fiber and fiber debond coating instability in the radioactive environment, 2) the low densities (85%) that are typical of SiC(f)/SiC composites, and 3) the high fabrication costs of SiC(f)/SiC CFCCs. This project will overcome problem #1 by using a new crystalline SiC fiber and by developing an innovative TiO2 fiber-matrix interface coating. Problems #2 and #3 will be overcome through an innovative, low-cost SiC(f)/SiC processing technique that consists of electrophoretic infiltration of nano-SiC particles into the crystalline SiC fiber preform, followed by a reverse thermal gradient chemical vapor infiltration (RTG CVI) process to achieve 95% dense CFCC structures in one-tenth the time required for a conventional CVI process. In Phase I, the process described above will be optimized and then used to fabricate a composite architecture consisting of a thin SiC layer sandwiched between two 95% dense SiC(f)/SiC CFCC structures. The physical and mechanical properties of the CFCC material will be characterized and analyzed with particular attention on the critical properties for structural fusion reactor components. Commercial Applications and Other Benefits as described by the awardee: The fusion reactor components of interest include first wall structures, divertor structures, limiters, and other insulating or containment components. Additionally, several military and commercial applications exist for the proposed TiO2 fiber-matrix interface coating. These applications include; liquid and solid rocket thrusters, containment shells, turbocharger rotors and wheels, pump shafts, radiant tube burners and heat exchangers, bearing races, seals, and turbine components such as combustor liners and blisks._