METHOD FOR MAKING METAL BASED NANO-COMPOSITE MATERIAL

• US 20130098208A1
• Filed: 12/12/2011
• Published: 04/25/2013
• Est. Priority Date: 10/21/2011
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd., Tsinghua University
• Original Assignee: Hon Hai Precision Industry Co., Ltd., Tsinghua University
• Inventors: LI, Wen-Zhen, LIU, Shi-Ying
• Granted Patent: US 9,034,073 B2
• Time in Patent Office: Days
• US Class Current: 75/708
• CPC Class Codes: B22F 2202/01 Use of vibrations
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: C22C 47/08 by contacting the fibres or filaments with molten metal, e.g. by infiltrating the fibres or filaments placed in a mould C22C47/16 takes precedence
• CPC Class Codes: C22C 49/14 characterised by the fibres or filaments
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/90 having step or means utilizing mechanical or thermal property, e.g. pressure, heat

Abstract

A method for making a metal based nano-composite material is disclosed. In the method, a semi-solid state metal based material is provided. The semi-solid state metal based material is stirred and nano sized reinforcements are added into the semi-solid state metal based material to obtain a semi-solid state mixture. The semi-solid state mixture is heated to a temperature above a liquidus temperature of the metal based material, to achieve a liquid metal-nano sized reinforcement mixture. The liquid metal-nano sized reinforcement mixture is ultrasonically processed at a temperature above the liquidus temperature by conducting ultrasonic vibrations to the liquid metal-nano sized reinforcement mixture along different directions at the same time.

Claims

1. A method for making a metal based nano-composite material, the method comprising steps of:

providing a metal based material in a semi-solid state;

forming a semi-solid state mixture by mixing the metal based material in the semi-solid state with nano sized reinforcements;

heating the semi-solid state mixture to a temperature above a liquidus temperature of the metal based material, to achieve a liquid metal-nanosized reinforcement mixture; and

ultrasonically processing the liquid metal-nanosized reinforcement mixture at a temperature above the liquidus temperature by conducting ultrasonic vibrations to the liquid metal-nanosized reinforcement mixture simultaneously along different directions.

2. The method of claim 1, wherein the forming the semi-solid state mixture comprising steps of:

stirring the metal based material in the semi-solid state while adding the nano sized reinforcements into the metal based material.

3. The method of claim 1, wherein the ultrasonically processing is processed by using a multi-dimension high power ultrasonic apparatus comprising:

a high power ultrasonic wave generator; and

an amplitude transformer being connected to the high power ultrasonic wave generator at one end and comprising a radiating portion, the radiating portion along a length direction of the amplitude transformer comprising;

at least two main sections having different cross-sections, outer surfaces of the at least two main sections being both parallel to a length direction of the amplitude transformer; and

at least one connecting section, the at least one connecting section being connected between the at least two main sections.

4. The method of claim 3, wherein the at least one connecting section comprises an outer surface smoothly extending from the outer surface of the one of the at least two main sections to the outer surface of the other one of the at least two main sections.

5. The method of claim 4, wherein the outer surface of the at least one connecting section is a concave surface.

6. The method of claim 3, wherein a total length of the at least one connecting section takes a percentage of about 40% to about 60% of a length of the radiating portion.

7. The method of claim 3, wherein a distance between a liquid level of the liquid metal-nanosized reinforcement mixture and an end of the amplitude transformer away from the high power ultrasonic wave generator is equal to or greater than 30 centimeters.

8. The method of claim 3, wherein the amplitude transformer further comprises an extending portion, and the extending portion is connected to the high power ultrasonic wave generator at one end and the radiating portion at the other end.

9. The method of claim 8, wherein the extending portion extends from the liquid metal-nanosized reinforcement mixture.

10. The method of claim 3, wherein the ultrasonically processing further comprises steps of:

inserting the amplitude transformer into the liquid metal-nanosized reinforcement mixture in an off state; and

generating the ultrasonic vibrations by the high power ultrasonic wave generator after the amplitude transformer has been inserted into the liquid metal-nanosized reinforcement mixture.

11. The method of claim 1, wherein the providing the metal based material comprising steps of:

providing a metal based material in solid state;

heating the metal based material in solid state to a temperature about 50°

C. higher than a liquidus line of the metal based material to obtain a metal based material in liquid state;

decreasing the temperature of the metal based material to a temperature between the liquidus line and a solidus line of the metal based material.

12. The method of claim 1, wherein a material of the nano sized reinforcements comprises a material that is selected from the group consisting of carbon nanotubes, silicon carbides, aluminum oxides, boron carbides, and any combinations thereof.

13. The method of claim 1, wherein a weight percentage of the nano sized reinforcements is about 0.1% to about 5.0%.

14. The method of claim 1, wherein a frequency of the ultrasonic processing ranges from about 15 KHz to about 20 KHz, and a power of the ultrasonic processing is equal to or larger than 0.8 kilowatts.

15. The method of claim 1, wherein a time for the ultrasonic processing ranges from about 1 minute to about 60 minutes.

16. The method of claim 1, wherein an amount of the liquid metal-nanosized reinforcement mixture ranges from about 50 kilograms to about 100 kilograms.

17. The method of claim 1, further comprising a step of increasing the temperature of the liquid metal-nanosized reinforcement mixture to a casting temperature ranged from about 650°

C. to about 780°

C.

18. The method of claim 1, further comprising a step of cooling the liquid metal-nanosized reinforcement mixture.

19. The method of claim 18, wherein the step of cooling comprises steps of:

preheating a mold to a temperature ranging from about 200°

C. to about 300°

C.; and

casting the liquid metal-nanosized reinforcement mixture to the mold.