Patent ID: 7927523
Filing Date: 2011-04-19
Classification: C04B,F16D

Abstract:
1. A method of manufacturing a pitch-based carbon-carbon composite useful as a brake disc, comprising the following sequential steps: (i) providing an annular carbon fiber brake disc preform comprising a nonwoven fabric; (ii) heat-treating the carbon fiber preform at 1200-2540° C.; (iii) densifying the preform by infiltrating the carbon fiber brake disc preform with mesophase pitch to a density of 1.1 g/cc to 1.5 g/cc by resin transfer molding (RTM) processing, followed by carbonizing the pitch-infiltrated carbon fiber preform at 1200-2200° C. in an inert atmosphere; (iv) densifying the preform by infiltrating the carbon fiber brake disc preform with low cost, isotropic pitch having low to medium char yield by VPI processing, followed by carbonizing the pitch-infiltrated carbon fiber preform at 1200-2200° C. in an inert atmosphere to achieve a density in the carbon fiber preform of 1.5 g/cc to below 1.7 g/cc; and (v) densifying the preform by a single cycle of chemical vapor deposition (CVD) or chemical vapor infiltration (CVI) to provide a C-C composite which: (i.) has a rough laminar microstructure and is densified at a temperature of 1275° C., a pressure of 210 Ton, and a C/H ratio of 1/4; (ii.) has a smooth laminar microstructure and is densified at a temperature of 1200° C., a pressure of 630 Torr, and a C/H ratio of 1/4; or (iii.) has an isotropic microstructure and is densified at a temperature of 1425° C., a pressure of 630 Ton, and a C/H ratio of 1/4, wherein said C-C composite has a density higher than 1.7 g/cc.