Patent ID: 8268208

Claim:
A method comprising the sequential steps of: (a) carbonizing an annular nonwoven carbon fiber brake disc preform; (b) carrying out a first densification of the carbonized carbon fiber preform by chemical vapor deposition (“CVD”) or chemical vapor infiltration (“CVI”) to produce a carbonized fiber preform: (i.) having a rough laminar microstructure and a density of about 1.4 grams per cubic centimeter; (ii.) having a smooth laminar microstructure and a density of about 1.2 grams per cubic centimeter; or (iii.) having an isotropic microstructure and a density of about 1.0 gram per cubic centimeter; (c) densifying a product of step (b) with pitch by vacuum pitch infiltration or resin transfer molding processing; (d) carbonizing the preform at a temperature between about 1200° C. and 2000° C. in an inert atmosphere to remove non-carbon volatiles from the pitch and to open porosity in the pitch-infused preform; (e) densifying a product of step (d) with pitch by vacuum pitch infiltration or resin transfer molding processing; (f) carbonizing the preform at a temperature between about 1200° C. and 2000° C. in an inert atmosphere to remove non-carbon volatiles from the pitch and to open porosity in the pitch-infused preform; and (g) heat treating a resulting pitch-densified carbon-carbon composite brake disc preform.