Abstract: Carbon-Carbon composite products comprising laminate plies formed from the carbon fabric having pitch-based carbon strands of relatively high modulus of elasticity in the warp direction. The fill direction carbon strands have a relatively low modulus of elasticity when compared to the warp direction strands and have a substantially lower end count than the higher modulus warp direction strands. A carbonaceous matrix is integrated with the fabric plies in order to bond the plies together. The matrix material may be glassy carbon or more preferably a crystalline graphitized carbon. In forming such carbon-carbon composite products, a layup is established of a plurality of the carbon fabric plies impregnated with a carbon containing matrix material, typically a thermoset resin. The layup is cured or partially cured and then pyrolized to a temperature sufficient to carbonize the matrix material.

Abstract: The invention provides a composition of matter comprising silicon, silicon carbide and boron carbide as a coating for protecting carbon substrates from degradation at elevated temperatures. The invention also provides a method for forming a protective coating on carbon substrates by utilizing the aforesaid composition of matter.

Abstract: There are provided improved processes for the manufacture of enriched pitches, carbon fiber precursors, carbon fibers, and graphite fibers. The improvement comprises employing an elevated wiped-film evaporator in a wiped-film evaporator system comprising the wiped-film evaporator and a means for recovering enriched pitch, such as a positive displacement pump, to form an enriched pitch from catalytic pitch and regulating the operating conditions of the wiped-film evaporator system to provide the desired enriched pitch. The wiped-film evaporator is located a specific distance above the means for recovering enriched pitch. The vertical distance between the outlet of the wiped-film evaporator and the inlet of the means for recovering enriched pitch is within the range of about 10 feet to about 40 feet, preferably about 20 feet to about 40 feet.

Abstract: There are provided improved processes for the manufacture of enriched pitches, carbon fiber precursors, carbon fibers, and graphite fibers. The improvement comprises employing an elevated wiped-film evaporator in a wiped-film evaporator system comprising the wiped-film evaporator and a means for recovering enriched pitch, such as a positive displacement pump, to form an enriched pitch from catalytic pitch and regulating the operating conditions of the wiped-film evaporator system to provide the desired enriched pitch. The wiped-film evaporator is located a specific distance above the means for recovering enriched pitch. The vertical distance between the outlet of the wiped-film evaporator and the inlet of the means for recovering enriched pitch is within the range of about 10 feet to about 40 feet, preferably about 20 feet to about 40 feet.

Abstract: Disclosed herein is an improved pitch for making readily stabilizable, substantially nonmesophasic carbon fibers. The pitch has a softening point of about 250.degree. C. (480.degree. F.) or above and is produced from an unoxidized thermal petroleum pitch by selectively reducing or eliminating a portion of the low molecular weight materials in a very short period of time so that the tendency to produce mesophase pitch is eliminated or reduced and so that the chemical integrity of the components of the higher molecular weight fractions is preserved as much as possible. Also disclosed is a method of producing carbon fibers therefrom and rovings or mats from such fibers.

Abstract: A method of compounding graphitizable compositions and improving the dispersion of filler particles and binder which comprises introducing the carbon filler into a hot-shear mixer, adding from about 25 to about 70 pph of water, adding from about 1/4 to about 5 pph of a dispersant, mixing for about 1/2 hour at a temperature at least above the boiling point of water (100.degree.), adding a binder, and mixing for about an additional one hour at a temperature above the melting point of the binder.