Loading patent…
AssigneeGrafTech International Holdings Inc.
InventorsDouglas J. Miller, Irwin C. Lewis, Richard L. Shao, Mehmet Suha Yazici
Estimating the term…
A reinforced carbon foam material is formed from carbon fibers incorporated within a carbon foam's structure. First, carbon fiber bundles are combined with a liquid resol resin. The carbon fiber bundles separate into individual carbon fiber filaments and disperse throughout the liquid resol resin. Second, the carbon fiber resin mixture is foamed thus fixing the carbon fibers in a permanent spatial arrangement within the phenolic foam. The foam is then carbonized to create a carbon fiber reinforced foam with improved graphitic characteristics as well as increased strength. Optionally, various additives can be introduced simultaneously with the addition of the carbon fiber bundles into the liquid resol, which can improve the graphitic nature of the final carbon foam material and/or increase the foam's resistance to oxidation.
A method for creating a reinforced resin-derived carbon foam material, comprising:
The method of claim 11 wherein in step a) the concentration of the carbon fiber bundles in the resin is from about 0.5% to about 10% by weight.
The method of claim 11 wherein the liquid phenolic resin has a water content of from about 10% to about 40% by weight.
The method of claim 11 wherein step a) is performed at room temperature.
The method of claim 11 wherein step a) further comprises mixing a additive with the liquid phenolic resin to improve the electrical and thermal conductivities of the reinforced carbon foam material wherein the graphitization additive is selected from the group consisting of metal powders, graphite powders, graphite flakes, and combinations thereof.
The method of claim 11 wherein step a) further comprises mixing a protective additive with the liquid phenolic resin to provide oxidation protection for the reinforced carbon foam material wherein the protective additive is selected from the group consisting of a polycarbosilane polymers, silicon-nitrogen polymers and combinations thereof.
A reinforced carbon foam comprising carbon fiber filaments dispersed throughout the carbon foam.
The foam of claim 17 further wherein the carbon fiber filaments provide an improved parallel alignment of the carbon foam's graphitic structure along the ligaments of the carbon foam.
The foam of claim 17 wherein the carbon fiber filaments have a length of from about 0.1 inches to about 1.0 inches.
The foam of claim 17 wherein each carbon fiber filament has a diameter of from about 5 microns to about 20 microns.
The foam of claim 17 wherein each carbon fiber filament has a tensile strength of from about 100,000 psi to about 600,000 psi.
The foam of claim 17 wherein each carbon fiber filament has a Young's modulus of from about 10,000,000 psi to about 100,000,000 psi.
The foam of claim 17 wherein the carbon fiber filaments are selected from the group consisting of mesophase pitch carbon fibers, isotropic pitch carbon fibers, carbonized rayon fibers, cotton fibers, polyacrylonitrile (PAN) carbon fibers, cellulose fibers, carbon nanofibers, carbon nanotubes, and combinations thereof.
The foam of claim 17 further comprising carbonized phenolic microballoons dispersed throughout the carbon foam.
Dependencies are inferred from the claim text.