Method of synthesizing aluminum carbon nanotube materials for structural and conductor applications

Patent metadata

Field	Value
Publication number	US-9973062-B2
Application number	US-201414319287-A
Country	US
Kind code	B2
Filing date	Jun 30, 2014
Priority date	Jun 30, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A method of in situ formation of an aluminum carbon nanotube composite material and an induction motor component produced with such composite. The method includes forming an aluminum-based matrix by mixing a catalyst precursor with an aluminum powder such that a colloidal compound is formed that is subsequently sintered to leave a catalytically-active material formed on the surface of the aluminum powder. A carbon-containing gas is introduced to the composite catalyst that includes aluminum and the catalytic metal so that carbon nanotube reinforcements are grown on the aluminum-based matrix with the assistance of the catalytically-active metal. Additional mechanical processing steps may also include pressurizing, sintering and cold-rolling the aluminum carbon nanotube composite material.

First claim

We claim:

1. A method of in situ formation of and processing of an aluminum carbon nanotube composite material, the method comprising:
forming an aluminum-based matrix comprising:
mixing a catalyst precursor with an aluminum powder such that a colloidal compound is formed; and
sintering said colloidal compound such that a catalytically-active material forms on the surface of said aluminum powder; and
growing carbon nanotube reinforcement on said aluminum-based matrix with said catalytically-active material to form an aluminum carbon nanotube composite material,
pressurizing said aluminum carbon nanotube composite material;
sintering said pressurized aluminum carbon nanotube composite material; and
cold-rolling said sintered, pressurized aluminum carbon nanotube composite material at a pressure sufficient to deform and elongate the aluminum-based matrix.

2. The method of claim 1 , wherein said catalyst precursor comprises a metal-containing solution.

3. The method of claim 2 , wherein said metal-containing solution is nickel-based.

4. The method of claim 3 , wherein said nickel-based metal-containing solution comprises Ni(NO 3 ) 2 .6(H 2 O).

5. The method of claim 3 , wherein said nickel-based metal-containing solution further comprises Y(NO 3 ) 3 -6(H 2 O).

6. The method of claim 5 , wherein an atomic ratio of yttrium to nickel to aluminum is 1:4:53.

7. The method of claim 3 , wherein up to about ten percent of said colloidal compound by weight is made up of said catalyst precursor.

8. The method of claim 3 , wherein said mixing a catalyst precursor with an aluminum powder such that a colloidal compound is formed further comprises adding a sodium hydroxide solution such that a three-way colloidal solution comprising Ni(NO 3 ) 2 .6(H 2 O), Y(NO 3 ) 3 -6(H 2 O), and aluminum powder is formed.

9. The method of claim 1 , wherein said sintering of said colloidal compound takes place in an inert environment.

10. The method of claim 9 , wherein said sintering of said colloidal compound takes place at a temperature of about 500 Celsius.

11. The method of claim 1 , wherein said growing carbon nanotube reinforcement comprises exposing said catalytically-active material to a carbon-containing gas.

12. The method of claim 11 , wherein said exposing takes place through chemical vapor deposition.

13. The method of claim 12 , wherein said carbon-containing gas comprises a mixture of nitrogen and at least one of ethylene, methane and formaldehyde.

14. The method of claim 13 , wherein said catalytically-active material is exposed to said mixture of nitrogen and methane in a temperature environment of between about 600 Celsius and about 650 Celsius for up to 10 minutes.

15. The method of claim 1 , wherein said pressurizing takes place at between about 200 MPa and about 250 MPa.

16. The method of claim 1 , wherein said sintering of said pressurized aluminum carbon nanotube composite material takes place at a temperature between about 550 Celsius and about 650 Celsius.

17. The method of claim 1 , wherein said cold-rolling takes place at a pressure of between about 400 MPa and about 600 MPa.

18. A method of in situ formation of and processing of an aluminum carbon nanotube composite material, the method comprising:
forming an aluminum-based matrix comprising:
mixing a nickel-containing catalyst precursor with an aluminum powder such that a colloidal compound is formed; and
sintering said colloidal compound such that a nickel-based catalytically-active material forms on the surface of said aluminum powder;
growing carbon nanotube reinforcement on said aluminum-based matrix with said catalytically-active material by exposing said catalytically-active material to a carbon-containing gas to form an aluminum carbon nanotube composite material; and
subjecting said aluminum carbon nanotube composite material to cold-rolling at a pressure sufficient to deform and elongate the aluminum-based matrix.

19. A method of forming a rotor for an induction motor, said method comprising:
preparing a plurality of conductor bars made from an aluminum carbon nanotube composite material, said carbon nanotube material made by:
forming an aluminum-based matrix comprising:
mixing a catalyst precursor with an aluminum powder such that a colloidal compound is formed; and
sintering said colloidal compound such that a nickel-based catalytically-active material forms on the surface of said aluminum powder;
growing carbon nanotube reinforcement on said aluminum-based matrix with said catalytically-active material by exposing said catalytically-active material to a carbon-containing gas to form an aluminum carbon nanotube composite material; and
subjecting said aluminum carbon nanotube composite material to a cold-rolling operation at a pressure sufficient to deform and elongate the aluminum-based matrix;
placing said conductor bars into a plurality of substantially longitudinal slots defined within a laminated steel stack; and
combining a pair of rings on respective ends of said plurality of conductor bars such that a cage and is defined thereby, said cage and said stack cooperative with one another to define respective electric current-compatible and magnetic flux-compatible portions of said rotor.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Wang Qigui
• Liu Xinkuan

Classifications

• H02K17/165

  Electricity · mapped topic

• B22F1/02

  Operations & Transport · mapped topic

• B22F3/18

  by using pressure rollers · CPC title

• H02K15/0012 Primary

  Electricity · mapped topic

• H02K3/02

  Windings characterised by the conductor material · CPC title