Pitch-based carbon foam and composites
OwnerJames W. Klettinventor
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Abstract
A process for producing carbon foam or a composite is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications.
Claims46
An essentially graphitic carbon foam having pore sizes in the range of about 90 microns to about 200 microns produced by a process comprising:
- providing pitch in a container;
- heating said pitch in a non-oxidizing atmosphere at a pressure to a temperature sufficient to coalesce said pitch to form a liquid of said pitch;
- increasing said pressure of said non-oxidizing atmosphere in said container containing said liquid of said pitch from said pressure to an increased pressure having a range greater than said pressure to about 1000 psi to form a carbon foam;
- heating said carbon foam in said non-oxidizing atmosphere to a temperature sufficient to carbonize said carbon foam to form a carbonized carbon foam;
- and
- heating said carbonized carbon foam to a temperature sufficient to form a thermal conducting essentially graphitic carbon foam having a bulk thermal conductivity of from 58 W/m·K to about 106 W/m·K and a specific thermal conductivity greater than 100 W·cm3/m·K·g.
An essentially graphitic carbon foam having a bulk thermal conductivity/density greater than 100 W·cm3/m·K·g, produced by a process comprising:
- providing pitch in a container;
- heating said pitch in a non-oxidizing atmosphere at a pressure to a temperature sufficient to coalesce said pitch to form a liquid of said pitch;
- increasing said pressure of said non-oxidizing atmosphere in said container containing said liquid of said pitch from said pressure to an increased pressure having a range greater than said pressure to about 1000 psi to form a carbon foam;
- heating said carbon foam in said non-oxidizing atmosphere to a temperature sufficient to carbonize said carbon foam to form a carbonized carbon foam;
- and
- heating said carbonized carbon foam to a temperature sufficient to form a thermal conducting essentially graphitic carbon foam having a specific thermal conductivity greater than an essentially amorphous carbon foam.
An essentially graphitic carbon foam having a specific thermal conductivity greater than copper.
An essentially graphitic carbon foam having a bulk thermal conductivity/density greater than 100 W·cm3/m·K·g.
An essentially graphitic carbon foam having a bulk thermal conductivity of from 58 W/m·K to about 106 W/m·K and a specific thermal conductivity greater than 100 W·cm3/m·K·g.
An essentially graphitic carbon foam having a bulk thermal conductivity of at least 58 W/m·K and a specific thermal conductivity greater than 100 W·cm3/m·K·g.
A non-oxidatively stabilized, essentially graphitic carbon foam of substantially open cell structure comprising cell walls wherein carbon derived from a mesophase pitch is in the form of graphite and substantially aligned along the cell wall axes.
A pitch-derived, non-oxidatively stabilized, essentially graphitic carbon foam, said foam having a bulk thermal conductivity of at least 58 W/m·K and a specific thermal conductivity greater than 100 W·cm3/m·K·g, said foam being further characterized by an open cell pore structure substantially comprised of ellipsoidal pores and by graphite substantially aligned along the axes of the cell walls.
An essentially graphitic carbon foam having a bulk thermal conductivity from about 58 W/m·K to about 106 W/m·K and a specific thermal conductivity greater than 100 W·cm3/m·K·g, said foam characterized by an X-ray diffraction pattern having an average d002 spacing of about 0.336 nm.
Dependencies are inferred from the claim text.