FORMATION OF SILICON CARBIDE-SILICON NITRIDE NANOPARTICLE CARBON COMPOSITIONS

• US 20130196844A1
• Filed: 03/11/2013
• Published: 08/01/2013
• Est. Priority Date: 01/26/2012
• Status: Active Grant

• Current Assignee: The Government Of The United States As Represented By The Secretary Of The Navy
• Original Assignee: The Government Of The United States Of America, As Represented By The Secretary Of The Navy
• Inventors: Keller, Teddy M., Saab, Andrew, Laskoski, Matthew, Qadri, Syed B.
• Granted Patent: US 8,778,488 B2
• Time in Patent Office: Days
• US Class Current: 501/90
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 32/956 Silicon carbide
• CPC Class Codes: C01B 32/984 Preparation from elemental silicon
• CPC Class Codes: C01B 32/991 Boron carbide
• CPC Class Codes: C04B 2235/383 Alpha silicon carbide
• CPC Class Codes: C04B 2235/3834 Beta silicon carbide
• CPC Class Codes: C04B 2235/3873 Silicon nitrides, e.g. silicon carbonitride, silicon oxynitride
• CPC Class Codes: C04B 2235/421 Boron
• CPC Class Codes: C04B 2235/422 Carbon
• CPC Class Codes: C04B 2235/428 Silicon
• CPC Class Codes: C04B 2235/48 Organic compounds becoming part of a ceramic after heat treatment, e.g. carbonising phenol resins
• CPC Class Codes: C04B 2235/5216 Inorganic
• CPC Class Codes: C04B 2235/5248 Carbon, e.g. graphite
• CPC Class Codes: C04B 2235/526 characterised by the length of the fibers
• CPC Class Codes: C04B 2235/5288 Carbon nanotubes
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/762 Cubic symmetry, e.g. beta-SiC
• CPC Class Codes: C04B 2235/767 Hexagonal symmetry, e.g. beta-Si3N4, beta-Sialon, alpha-SiC or hexa-ferrites
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/781 : Nanograined materials, i.e. having grain sizes below 100 nm
• CPC Class Codes: C04B 2235/80 : Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 2235/95 : Products characterised by their size, e.g. microceramics
• CPC Class Codes: C04B 35/52 : based on carbon, e.g. graphite
• CPC Class Codes: C04B 35/522 : Graphite C04B35/536 takes precedence
• CPC Class Codes: C04B 35/524 : obtained from polymer precursors, e.g. glass-like carbon material
• CPC Class Codes: C04B 35/573 : obtained by reaction sintering or recrystallisation
• CPC Class Codes: C04B 35/591 : obtained by reaction sintering
• CPC Class Codes: C04B 35/76 : Fibres, filaments, whiskers, platelets, or the like
• CPC Class Codes: C04B 35/80 : Fibres, filaments, whiskers, platelets, or the like
• CPC Class Codes: C04B 35/83 : Carbon fibres in a carbon matrix
• CPC Class Codes: Y10T 428/249956 : Void-containing component is inorganic
• CPC Class Codes: Y10T 428/249957 : Inorganic impregnant

Abstract

A composition having nanoparticles of silicon carbide and a carbonaceous matrix or silicon matrix. The composition is not in the form of a powder. A composition having silicon and an organic compound having a char yield of at least 60% by weight or a thermoset made from the organic compound. A method of combining silicon and the organic compound and heating to form silicon carbide or silicon nitride nanoparticles.

Claims

1. A composition comprising:

nanoparticles of silicon carbide; and

a carbonaceous matrix or silicon matrix;

wherein the composition is not in the form of a powder.

2. The composition of claim 1, wherein the composition comprises at least 5% by weight of the nanoparticles.

3. The composition of claim 1, wherein the composition comprises at least 99% by weight of the nanoparticles.

4. The composition of claim 1, wherein the average diameter of the nanoparticles is less than 100 nm.

5. The composition of claim 1, wherein the nanoparticles comprise α

-SiC.

6. The composition of claim 1, wherein the nanoparticles comprise β

-SiC.

7. The composition of claim 1, wherein the carbonaceous matrix comprises graphitic carbon, carbon nanotubes, or amorphous carbon.

8. The composition of claim 1, wherein the composition further comprises:

nanoparticles comprising silicon nitride.

9. The composition of claim 1, wherein the composition further comprises:

nanoparticles comprising silicon boron carbide.

10. The composition of claim 1, wherein the composition further comprises:

fibers, carbon fibers, ceramic fibers, or metal fibers.

11. The composition of claim 1, wherein the composition contains less than 20% by volume of voids.

12. An article comprising the composition of claim 1, wherein the article is in the form of a solid, unbroken mass having a minimum size of at least 1 mm in all dimensions.

13. A composition comprising:

silicon; and

an organic component selected from;

an organic compound having a char yield of at least 60% by weight; and

a thermoset made from the organic compound.

14. The composition of claim 13, wherein the organic compound:

contains only carbon and hydrogen;

contains aromatic and acetylene groups;

contains only carbon, hydrogen, and nitrogen or oxygen;

contains no oxygen;

or

contains a heteroatom other than oxygen.

15. The composition of claim 13, wherein the organic compound is 1,2,4,5-tetrakis(phenylethynyl)benzene or a prepolymer thereof, 4,4′

-diethynylbiphenyl, N, N′

-(1,4-phenylenedimethylidyne)-bis-(3-ethynylaniline), dianilphthalonitrile, or resorcinol phthalonitrile or a prepolymer thereof.

16. The composition of claim 13, wherein the composition further comprises:

boron.

17. The composition of claim 13, wherein the composition further comprises:

fibers, carbon fibers, ceramic fibers, or metal fibers.

18. The composition of claim 13, wherein the composition is a shaped component having the silicon dispersed in the thermoset.

19. A method comprising:

combining silicon and an organic compound having a char yield of at least 60% by weight to form a precursor mixture.

20. The method of claim 19, further comprising:

placing the precursor mixture into a mold or shaped reactor.

21. The method of claim 19, further comprising:

forming the precursor mixture into a shaped component.

22. The method of claim 19, further comprising:

heating the precursor mixture in an inert atmosphere or vacuum at a temperature that causes polymerization of the organic compound to a thermoset to form a thermoset composition.

23. The method of claim 22, wherein heating the precursor mixture is performed at 150-600°

C.

24. The method of claim 22, further comprising:

heating the thermoset composition in an inert atmosphere, argon, nitrogen, or vacuum at a temperature that causes formation of a carbonized thermoset having silicon embedded therein.

25. The method of claim 24, wherein heating the thermoset composition is performed at 600-1400°

C.

26. The method of claim 22, further comprising:

heating the thermoset composition in an inert atmosphere, argon, nitrogen, or vacuum at a temperature that causes formation of a ceramic comprising nanoparticles of silicon carbide or silicon nitride in a carbonaceous matrix or silicon matrix.

27. The method of claim 26;

wherein the precursor mixture further comprises boron; and

wherein heating the thermoset composition causes formation of nanoparticles of silicon boron carbide.

28. The method of claim 26, wherein heating the thermoset composition is performed at 1400-1900°

C.

29. The method of claim 26, wherein heating the thermoset composition is performed at greater than 1900°

C.

30. The method of claim 26, wherein heating the thermoset composition is performed above the melting point of the silicon.

31. A method comprising:

providing a precursor mixture of silicon and an organic compound;

heating the precursor mixture in an inert atmosphere or vacuum at elevated pressure and at a temperature that causes polymerization of the organic compound to a thermoset to form a thermoset composition; and

heating the thermoset composition in an inert atmosphere, argon, nitrogen, or vacuum at a temperature that causes formation of a ceramic comprising nanoparticles of silicon carbide or silicon nitride in a carbonaceous matrix or silicon matrix;

wherein the organic compound has a char yield of at least 60% by weight when heated at the elevated pressure.