PRESSURE INFILTRATION OF NET-SHAPE GRAPHITE PERFORMS FOR METAL MATRIX COMPOSITES

MUCH OF THE COST OF ADVANCED COMPOSITES IS DUE TO FIBER HANDLING AND CONSOLIDATION. THESE "FIBER PLACEMENT" COSTS RISE AS THE SHAPE OF THE COMPONENT BECOMES MORE COMPLEX AND AS THE NUMBER OF REINFORCED DIRECTIONS INCREASES. THIS PROJECT WILL INVESTIGATE A NEW METHOD FOR PRODUCING THREE-DIMENSIONAL, CARBON-REINFORCED METAL-MATRIX COMPOSITES. ALL FIBER-HANDLING STEPS ARE ELIMINATED THROUGHTHE USE OF A NEW PREFORM MATERIAL. THIS NOVEL MATERIAL IS PRODUCED BY IN-SITU CREATION OF VAPOR-GROWN CARBON FIBER (VGCF) UPON A MOLDED CARBON SCAFFOLD. VGCF HAS A UNIQUE MORPHOLOGY THAT MAY ACT AS A MECHANICAL FUSE TO IMPROVE COMPOSITE TOUGHNESS. ALTHOUGH PRODUCED FROM INEXPENSIVE HYDRO-CARBON GASES, VCCF'S PROPERTIES APPROACH THOSE OF SINGLE CRYSTAL GRAPHITE, INCLUDING A MODULUS OF 87 MSI, STRENGTH OF 1.0 MSI, AND THERMAL CONDUCTIVITY OF 1950 W/M K. METAL-MATRIX COMPOSITES WILL BE FABRICATED USING A PRESSURE INFILTRATION TECHNIQUE DEVELOPED BY JAMES CORNIE, DIRECTOR OF THE LABORATORY FOR INORGANIC COMPOSITES AT MIT. MUCH OF THE COST OF ADVANCED COMPOSITES IS DUE TO FIBER HANDLING AND CONSOLIDATION. THESE "FIBER PLACEMENT" COSTS RISE AS THE SHAPE OF THE COMPONENT BECOMES MORE COMPLEX AND AS THE NUMBER OF REINFORCED DIRECTIONS INCREASES. THIS PROJECT WILL INVESTIGATE A NEW METHOD FOR PRODUCING THREE-DIMENSIONAL, CARBON-REINFORCED METAL-MATRIX COMPOSITES. ALL FIBER-HANDLING STEPS ARE ELIMINATED THROUGHTHE USE OF A NEW PREFORM MATERIAL. THIS NOVEL MATERIAL IS PRODUCED BY IN-SITU CREATION OF VAPOR-GROWN CARBON FIBER (VGCF) UPON A MOLDED CARBON SCAFFOLD. VGCF HAS A UNIQUE MORPHOLOGY THAT MAY ACT AS A MECHANICAL FUSE TO IMPROVE COMPOSITE TOUGHNESS. ALTHOUGH PRODUCED FROM INEXPENSIVE HYDRO-CARBON GASES, VCCF'S PROPERTIES APPROACH THOSE OF SINGLE CRYSTAL GRAPHITE, INCLUDING A MODULUS OF 87 MSI, STRENGTH OF 1.0 MSI, AND THERMAL CONDUCTIVITY OF 1950 W/M K. METAL-MATRIX COMPOSITES WILL BE FABRICATED USING A PRESSURE INFILTRATION TECHNIQUE DEVELOPED BY JAMES CORNIE, DIRECTOR OF THE LABORATORY FOR INORGANIC COMPOSITES AT MIT.