Ultrasonic energy system and method including a ceramic horn

• US 20040190733A1
• Filed: 03/31/2003
• Published: 09/30/2004
• Est. Priority Date: 03/31/2003
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Gerdes, Ronald W., Nayar, Satinder K., Amin, Kamal E., Carpenter, Michael W.
• Granted Patent: US 7,297,238 B2
• Time in Patent Office: Days
• US Class Current: 381/98
• CPC Class Codes: B06B 3/00 Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
• CPC Class Codes: B21C 1/006 using vibratory energy
• CPC Class Codes: B21C 37/042 Manufacture of coated wire or bars
• CPC Class Codes: B22D 19/14 the objects being filamentary or particulate in form making alloys containing fibres or filaments by contacting the fibres or filaments with molten metal C22C47/08
• 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: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00

Abstract

An acoustic system for applying vibratory energy including a horn connected to an ultrasonic energy source. The horn defines an overall length and wavelength, and at least a leading section thereof is comprised of a ceramic material. The leading section has a length of at least ⅛ the horn wavelength. In one preferred embodiment, an entirety of the horn is a ceramic material, and is mounted to a separate component, such as a waveguide, via an interference fit. Regardless, by utilizing a ceramic material for at least a significant portion of the horn, the ultrasonic system of the present invention facilitates long-term operation in extreme environments such as high temperature and/or corrosive fluid mediums. The present invention is useful for fabrication of metal matrix composite wires.

Claims

1. An acoustic system for applying vibratory energy, the system comprising:

a horn connected to an ultrasonic energy source, the horn defining a length and a wavelength, wherein at least a leading section of the horn is comprised of a ceramic material, the leading section having a length of at least ⅛

the horn wavelength.

2. The system of claim 1, wherein the leading section has a length of at least ¼

the horn wavelength.

3. The system of claim 1, wherein an entirety of the horn is a ceramic material.

4. The system of claim 1, wherein the ceramic material includes at least one ceramic selected from silicon nitride, aluminum oxide, sialon, titanium diboride, zirconia, or silicon carbide.

5. The system of claim 1, wherein the horn is a cylindrical rod.

6. The system of claim 1, wherein the horn is adapted for at least partial immersion in a high temperature fluid medium.

7. The system of claim 6, wherein the horn is adapted to transmit ultrasonic energy at a frequency of approximately 20 kHz to a molten metal-based medium and is characterized by a working life of at least 100 hours.

8. The system of claim 7, wherein the horn is characterized by a working life of at least 200 hours when immersed in a molten aluminum-based medium.

9. The system of claim 1, wherein the horn is defined by a trailing end and a leading end, and further wherein the ultrasonic energy source includes a mounting component for maintaining the trailing end of the horn, the horn being secured to the mounting component by a clamping mechanism.

10. The system of claim 9, wherein the horn is interference fitted to the mounting component.

11. The system of claim 9, wherein the mounting component is selected from the group consisting of a waveguide and a booster.

12. The system of claim 9, wherein the horn is a ceramic cylindrical rod and the mounting component defines a circular bore, and further wherein the trailing end of the horn is received within the circular bore.

13. The system of claim 12, wherein the mounting component and the horn are adapted to maintain an interference fit at a temperature of at least 200°

C.

14. The system of claim 13, wherein the mounting component and the horn are adapted to maintain an interference fit at a temperature of at least 350°

C.

15. The system of claim 12, wherein the mounting component includes a material selected from titanium or steel.

16. The system of claim 9, further comprising:

a tubular shroud surrounding a junction between the mounting component and the horn; and

an air source fluidly connected to the shroud for delivering air through the shroud to cool the junction.

17. The system of claim 1, further comprising:

a transducer for changing electrical energy into ultrasonic vibration;

a booster for increasing an amplitude of the vibration; and

a waveguide component for transferring the amplified vibration to the horn.

18. A method of applying ultrasonic energy in a fluid medium, the method comprising:

providing a fluid medium;

connecting an ultrasonic energy source to a horn, at least a leading ⅛

wavelength of which is ceramic;

immersing at least a leading portion of the horn in the fluid medium; and

operating the ultrasonic energy source such that the horn delivers ultrasonic energy to the fluid medium.

19. The method of claim 18, wherein the fluid medium has a temperature of at least 200°

C.

20. The method of claim 19, wherein the fluid medium has a temperature of at least 600°

C.

21. The method of claim 19, wherein the fluid medium is corrosive.

22. The method of claim 21, wherein the corrosive fluid medium is a molten metal.

23. The method of claim 18, wherein an entirety of the horn is ceramic, and further wherein connecting an ultrasonic energy source to the horn includes:

providing a metal mounting component as part of the ultrasonic energy source; and

interference fitting a trailing end of the horn to the mounting component.

24. The method of claim 18, wherein the fluid medium is molten aluminum, and further wherein the method is characterized by not replacing the horn for at least 100 hours of ultrasonic energy delivery.

25. The method of claim 18, wherein the ultrasonic energy source includes a metal waveguide component maintaining the horn via an interference fit, the method further comprising:

determining a desired resonant frequency of the horn; and

adjusting a length of the waveguide component based upon the desired resonant frequency.

26. The method of claim 18, wherein the delivered ultrasonic energy causes infiltration of a molten metal matrix material into a plurality of fibers immersed in the molten metal matrix.

27. A method of making a continuous composite wire, the method comprising:

providing a contained volume of molten metal matrix material having a temperature of at least 600°

C.;

immersing at least one tow comprising a plurality of substantially continuous fibers into the contained volume of molten metal matrix material;

imparting ultrasonic energy with a horn, at least a leading ⅛

wavelength of which is ceramic, to cause vibration of at least a portion of the contained volume of molten metal matrix material to permit at least a portion of the molten metal matrix material to infiltrate into the plurality of fibers such that an infiltrated plurality of fibers is provided; and

withdrawing the infiltrated plurality of fibers from the contained volume of molten metal matrix material.

28. The method of claim 27, wherein an entirety of the horn is ceramic.

29. The method of claim 27, wherein continuous composite wires are fabricated for at least 100 hours without replacing the horn.