Abstract: A high-temperature compressible material especially useful in rocket motors to support nozzle ring inserts, the material including a binder which when pyrolyzed leaves a char having substantial strength, and fillers including carbonaceous fillers such as carbon fibers, wools, powders, etc., plus a special filler comprising hollow carbon microspheres which can crush to provide a compressibility to the material when it is confined in a volume-limiting environment, plus other fillers which may be added to obtain special yield characteristics.

Abstract: A method for making said rigid pyrolytic graphite article comprising winding a continuous, individual, refractory filament or strand around a shaped form and simultaneously pyrolyzing a mixture of methyl trichlorosilane and a hydrocarbon gas onto the filament or strand at about the point of winding contact to nucleate pyrolytic graphite and SiC from the filament or strand, winding additional turns of the filament or strand around the form, each additional turn being spaced from previously wound turns and, as each of the additional turns is wound, simultaneously pyrolyzing the mixture of methyl trichlorosilane and hydrocarbon gas thereon at about the point of winding contact and on the codeposited pyrolytic graphite and SiC nucleated from previously wound turns.

Abstract: A rigid pyrolytic graphite microcomposite material comprising a matrix of pyrolytic graphite containing embedded therein codeposited crystalline silicon carbide comprising aciculae oriented approximately perpendicular to the a-b plane of the crystallite layers of the pyrolytic graphite. The SiC comprises at least about 5 volume percent of the microcomposite material, preferably at least about 10 volume percent.A method for making said microcomposite material comprising pyrolyzing a mixture of methyl trichlorosilane and a hydrocarbon gas at temperatures of about 2800.degree. F to 4000.degree. F, preferably about 3200.degree. F to 3800.degree. F and, thereby codepositing pyrolytic graphite and SiC.A rigid composite pyrolytic graphite article comprising a matrix of the above microcomposite material containing embedded therein at least one reinforcing refractory filament or strand layer.