Process for preparing silicon carbide foam
AssigneeSandia Corporation
InventorsLeRoy Louis Whinnery, Monte Carl Nichols, David Roger Wheeler, Douglas Anson Loy
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Abstract
A method of preparing near net shape, monolithic, porous SiC foams is disclosed. Organosilicon precursors are used to produce polymeric gels by thermally induced phase separation, wherein, a sufficiently concentrated solution of an organosilicon polymer is cooled below its solidification temperature to form a gel. Following solvent removal from the gel, the polymer foam is pretreated in an oxygen plasma in order to raise its glass transition temperature. The pretreated foam is then pyrolized in an inert atmosphere to form a SiC foam.
Claims17
A method of preparing monolithic SiC foams, comprising steps of:
- a) dissolving an organosilicon polymer or copolymer in a solvent to form a solution;
- b) cooling the solution to form a gel;
- c) removing the solvent from the gel to form a polymer foam;
- d) stabilizing the polymer foam by subjecting the foam to a plasma;
- and
- e) pyrolyzing the stabilized foam in an inert gas at a temperature sufficient to decompose the stabilized polymer foam and thereby form a SiC foam.
Dependencies are inferred from the claim text.