Method for preparing a carbon/carbon composite

1. A method for preparing a carbon/carbon (C/C) composite comprising carbonizing a carbon fiber-reinforced polymer matrix composite precursor by heating the precursor in an inert atmosphere with a furnace at a temperature of 500-2000° C. with a heating rate greater than 20° C./min, wherein said precursor is heated without an exterior pressure being applied to said precursor.

2. The method as set forth in claim 1 , wherein the heating rate is greater than 100° C./min.

3. The method as set forth in claim 1 , wherein the heating rate is of 300-1500° C./min.

4. The method as set forth in claim 2 wherein the heating is carried out by using an open-end induction furnace, and wherein said precursor is continually or intermittently brought in and out said furnace.

5. The method as set forth in claim 2 , wherein the precursor is a cured carbon fiber-reinforced polymer matrix composite having a thickness less than 3.0 cm.

6. The method as set forth in claim 5 , wherein the precursor is a cured carbon fiber-reinforced polymer matrix composite having a thickness less than 2.0 cm.

7. The method as set forth in claim 5 , wherein the precursor is a cured carbon fiber-reinforced polymer matrix composite prepared from randomly oriented carbon fibers having a length greater than 3.0 mm and shorter than a length of the precursor.

8. The method as set forth in claim 7 , wherein the randomly oriented carbon fibers having a length shorter than 30% of the length of the precursor.

9. The method as set forth in claim 5 , wherein the precursor is a cured carbon fiber-reinforced polymer matrix composite prepared from a two-dimensional woven carbon fiber cloth, two-dimensional random fiber mat or a three-dimensional woven fiber preform.

10. The method as set forth in claim 5 , wherein the precursor is a cured carbon fiber-reinforced polymer matrix having 20-80 vol % of carbon fibers based on the volume of the cured carbon fiber-reinforced polymer matrix.

11. The method as set forth in claim 10 , wherein the cured carbon fiber-reinforced polymer matrix has 30-70 vol % of carbon fibers.

12. The method as set forth in claim 1 further comprising a first graphitization comprising heating the resulting carbonized composite in an inert atmosphere at a temperature higher than 2000° C.

13. The method as set forth in claim 12 further comprising densifying the resulting first graphitized composite by repeating one or more cycles of impregnating the first graphitized composite with a resin; curing the resin; and carbonizing the cured resin in the first graphitized composite.

14. The method as set forth in claim 1 further comprising densifying the resulting carbonized composite by repeating one or more cycles of impregnating the carbonized composite with a resin; curing the resin; and carbonizing the cured resin in the carbonized composite.

15. The method as set forth in claim 13 further comprising a second graphitization comprising heating the resulting densified composite in an inert atmosphere at a temperature higher than 2000° C.

16. The method as set forth in claim 15 further comprising subjecting the resulting second graphitized composite to a post-treatment comprising impregnating the second graphitized composite with a resin; curing the resin; carbonizing the cured resin in the second graphitized composite; and optionally graphitizing the carbonized second graphitized composite at a temperature higher than 2000° C.

17. The method as set forth in claim 14 , wherein said carbonizing in said densifying is carried out in an inert atmosphere and with a heating rate greater than 20° C./min.

18. The method as set forth in claim 16 , wherein said carbonizing in said post-treatment is carried out in an inert atmosphere and with a heating rate greater than 20° C./min.

19. The method as set forth in claim 1 , wherein said carbon fiber is selected from the group consisting of polyacrylonitrile (PAN)-derived carbon fiber, pitch-derived carbon fiber and rayon-derived carbon fiber.

20. The method as set forth in claim 1 , wherein said polymer is a thermosetting polymer or a thermoplastic polymer.

21. The method as set forth in claim 20 , wherein said thermosetting polymer is selected from the group consisting of phenolic resin, furfural alcohol resin and polyimide.

22. The method as set forth in claim 20 , wherein said thermoplastic polymer is selected from the group consisting of petroleum pitch, coal tar pitch, mesophase pitch and polyetheretherketone (PEEK).

23. The method as set forth in claim 1 , wherein said polymer is doped with a carbon-containing viscosity-modifying component selected from the group consisting of graphite, carbon black, mesophase pitch, carbon nanoparticle, carbon nanotube, and carbide.

24. The method as set forth in claim 16 , wherein said resin used in said post-treatment is a phenolic resin, a furfural alcohol resin, a petroleum pitch, a coal tar pitch or a mesophase pitch.

25. The method as set forth in claim 14 , wherein said resin used in said densifying is doped with a carbon-containing additive.

26. The method as set forth in claim 25 , wherein said carbon-containing additive is in an amount of 1-30% based on the weight of the resin.

27. The method as set forth in claim 25 , wherein said carbon-containing additive is selected from the group consisting of graphite, carbon black, mesophase pitch, carbon nanoparticle, carbon nanotube, and carbide.

28. The method as set forth in claim 16 , wherein said resin used in said post-treatment is doped with a carbon-containing additive.

29. The method as set forth in claim 28 , wherein said carbon-containing additive is in an amount of 1-30% based on the weight of the resin.

30. The method as set forth in claim 28 , wherein said carbon-containing additive is selected from the group consisting of graphite, carbon black, mesophase pitch, carbon nanoparticle, carbon nanotube, and carbide.

31. The method as set forth in claim 14 , wherein said carbonizing in said densifying is carried out in an inert atmosphere and with a heating rate greater than 100° C./min.

32. The method as set forth in claim 16 , wherein said carbonizing in said post-treatment is carried out in an inert atmosphere and with a heating rate greater than 100° C./min.

33. The method as set forth in claim 1 , wherein the heating is not resistive heating.

34. The method as set forth in claim 1 , wherein the heating does not require applying an electric current to the precursor.