Net shape manufacturing using carbon nanotubes

• US 6,495,116 B1
• Filed: 04/10/2000
• Issued: 12/17/2002
• Est. Priority Date: 04/10/2000
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Herman, Frederick James
• Primary Examiner(s): Hendrickson, Stuart L.
• Application Number:
  US09/546,081
• Time in Patent Office: 981 Days
• Field of Search: 423/447.3
• US Class Current: 423/447.3
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 32/162 characterised by catalysts
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/743 having specified tube end structure, e.g. close-ended shell or open-ended tube
• CPC Class Codes: Y10S 977/833 Thermal property of nanomaterial, e.g. thermally conducting/insulating or exhibiting peltier or seebeck effect
• CPC Class Codes: Y10S 977/843 Gas phase catalytic growth, i.e. chemical vapor deposition
• CPC Class Codes: Y10S 977/888 Shaping or removal of materials, e.g. etching

Abstract

The present invention provides methods and systems for net shaped manufacturing using carbon nanotubes. Generally, an automatic control unit is used to place reaction units in the proper location to produce a component part of carbon nanotubes in a predetermined configuration. The reaction units include a carbon vaporization unit, a carbon feed/injection unit and a gas pressure/temperature control isolation unit. The carbon feed/injection unit advantageously operates to inject carbon based materials (e.g., graphite powder, solid graphite or carbon based gas) into an reaction area at a predetermined rate in which the carbon vaporization unit provides energy capable of dissociating carbon atoms from the injected carbon based material to produce a predetermined concentration of carbon vapor within the reaction area. The gas pressure/temperature control isolation unit operates to control the pressure and temperature of the reaction area to promote the growth of carbon nanotubes.

Claims

1. A method of manufacturing a component part having a predetermined configuration using carbon nanotubes, comprising the steps of:

injecting carbon based material into a reaction area at a predetermined rate;

dissociating carbon atoms from said carbon based material at a predetermined rate;

maintaining the reaction area at a predetermined temperature and a predetermined pressure, wherein said carbon nanotubes nucleate in said reaction area;

performing said injecting, dissociating and maintaining steps to nucleate said carbon nanotubes in said predetermined configuration; and

repeating said step of performing said injecting, dissociating and maintaining for multiple cross-sectional layers with successive cross-sectional layers stacked on previous cross-sectional layers, wherein said predetermined configuration is determined by said multiple cross-sectional layers.

2. The method of claim 1 further comprising the step of adjusting the growth direction of said carbon nanotube during a growth period.

3. The method of claim 1 further comprising the step of varying the rate of injection of said carbon based material.

4. The method of claim 1 further comprising the step of varying the rate of dissociation from said carbon based material.

5. The method of claim 1 further comprising the step varying said predetermined pressure and predetermined temperature.

6. The method of claim 1, wherein the step of dissociating is effectuated by a laser, an electron beam, or an electrical arc discharge unit.

7. The method of claim 1, wherein said carbon based material further comprises a metal based material.

8. The method of claim 7, further comprising the step of varying the concentration of said metal based material.

9. The method of claim 1 further comprising the steps of:

injecting a carbon based material having a first metal based material; and

injecting a second carbon based material having a second metal based material.

10. A method of manufacturing a component part having a predetermined configuration using carbon nanotubes, comprising the steps of:

injecting a first carbon based material having a first metal based material and a second carbon based material having a second metal based material into a reaction area at a predetermined rate;

dissociating carbon atoms from said carbon based materials at a predetermined rate;

maintaining the reaction area at a predetermined temperature and a predetermined pressure, wherein said carbon nanotubes nucleate in said reaction area; and

performing said injecting, dissociating and maintaining steps to nucleate said carbon nanotubes in said predetermined configuration.

11. The method of claim 10 further comprising the step of:

repeating said step of performing said injecting, dissociating and maintaining steps for a plurality of cross-sectional layers with successive cross-sectional layers stacked on previous cross-sectional layers, wherein said predetermined configuration is determined by said plurality of cross-sectional layers.

12. The method of claim 10 further comprising the step of varying the rate of injection of said carbon based materials.

13. The method of claim 10 further comprising the step of varying the rate of dissociation from said carbon based materials.

14. The method of claim 10 further comprising the step varying said predetermined pressure and predetermined temperature.

15. The method of claim 10, wherein the step of dissociating is effectuated by one of a laser, an electron beam, and an electrical arc discharge unit.

16. The method of claim 10, further comprising the step of varying the concentration of one of said first metal based material and said second metal based material.

17. The method of claim 10, further comprising the step of adjusting the growth direction of said carbon nanotube during a growth period.