MECHANICAL-BEHAVIOR OF CARBON-CARBON COMPOSITES MADE WITH COLD-PLASMA TREATED CARBON-FIBERS

Carbon-carbon (C-C) composites offer unique structural characteristics including low density, high stiffness, high strength and high fracture toughness. Fibre-matrix interactions play a critical role in determining the load transfer between the fibre and matrix in these composites. This paper addresses the role of plasma fibre surface treatments in optimizing the mechanical properties of C-C composites made with surface treated fibres. Very short treatment times (less than 1 min) were found to be beneficial in introducing the desired fibre surface chemistry without degenerating the fibre's strength properties. C-C composites made with 30 s oxygen plasma treated fibres exhibited a 25% increase in flexure strength combined with a shear failure. Morphological and chemical characteristics of surface treated fibres are correlated with the mechanical properties of C-C composites.