An apparatus and method for forming a densified carbon-carbon composite.
The apparatus includes: a green part molding station for forming a green
part; a carbonization station for carbonizing the green part; and an
impregnation station for impregnating the carbonized part with a
substantially curing by-product free, high carbon yield resin. The
impregnation station includes a mold forming a sealed enclosure
configured in the shape of the carbonized part for receiving the
carbonized part and a vacuum source for evacuating the mold. At least one
resin injection port is in the mold and a supply of substantially curing
by-product free, high carbon yield resin is connected to the resin
injection port for injection into the mold. In the preferred embodiment,
the substantially curing by-product free, high carbon yield resin is a
cyanate ester having a viscosity of less than about 100 cps at
250.degree. F. and a carbon yield value of greater than about 60 wt. %.
The combination of a high carbon yield resin and a pressurized
impregnation station configured to the shape of the composite part for
use with a curing by-product free resin provides for a substantial
reduction in the number of carbonization cycles required to reach final
density while, at the same time avoids the environmental and safety
problems of a solvent-based system.