REFRACTORY METAL COATINGS ON CARBON/CARBON COMPOSITES FOR FIRST WALL APPLICATIONS

COMPOSITE MATERIALS HAVE BEEN DEVELOPED THAT POTENTIALLY YIELD A THERMAL CONDUCTIVITY OF UP TO 1000 W/M-K IN UNIAXIAL ORIENTATION. THIS YIELD IS SUFFICIENTLY HIGH TO ALLOW MULTIDIMENSIONAL DESIGNS THAT MEET OFF-AXIS THERMAL AND MECHANICAL PROPERTY CRITERIA AND MATCH THE COEFFICIENT OF THERMAL EXPANSION TO OTHER COMPONENTS WITHIN A RANGE OF 0 TO 10 X 10(-6) PPM. EXPLOITATION OF THESE ULTRAHIGH THERMALLY CONDUCTIVE COMPOSITES REQUIRES OPTIMIZING THE HEAT TRANSFER INTO AND OUT OF THE CONDUCTIVE COMPOSITE. CONVENTIONAL SOLID-STATE DIFFUSION AND BRAZING TECHNIQUES HAVE OPTIMIZED EITHER THERMAL OR MECHANICAL PROPERTIES OF THIS TYPE OF JOINT. THE OBJECTIVE OF THE PHASE I RESEARCH IS TO OPTIMIZE BOTH THE THERMAL AND MECHANICAL PROPERTIES OF JOINTS MADE BETWEEN HIGH THERMAL CONDUCTIVITY CARBON/CARBON COMPOSITES AND OTHER MATERIALS USING NOVEL ION BEAM ALLOYING METHODS. THIS RESEARCH WOULD OPTIMIZE LONG-TERM PERFORMANCE OF THE JOINT.