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US4671906A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for production of minute metal powder

Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1986-03-24
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Granted: 1987-06-09
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Expires: 2006-03-24
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Abstract

Abstract A minute metal powder is obtained by a method which comprises melting a metal, imparting ultrasonic vibration to the resulting melt, introducing an inert or reducing gas into the ultrasonically vibrated melt thereby producing minute bubbles therein, allowing cavitation to occur as soon as the bubbles reach the surface of the melt and consequently convert the melt into minute droplets, exposing or not exposing the minute droplets to oxygen, nitrogen, or propane, and solidifying the minute droplets by cooling. An apparatus for working the method described above comprises a metal melting tank, metal feeding means, gas feeding means, an ultrasonic vibration generator, means for detecting and retaining the surface of melt, and means for converting melt into minute droplets and solidifying the minute droplets by cooling.

Inventors

  • 👤 Kazuo Yasue
  • 👤 Toshiyuki Nishio
  • 👤 Mineo Kosaka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 15:54
CPC Classifications
B; B05; B05B; B05B17/00; B05B17/04; B05B17/06; B05B17/0607; B05B17/0623; B05B17/063; B01; B01J; B01J10/00; B01J10/005; B01J19/00; B01J19/08; B01J19/10; B01J2/00; B01J2/02; B01J2/04; B05B17/0615; B22; B22F; B22F9/00; B22F9/02; B22F9/06; C; C01; C01B; C01B13/00; C01B13/14; C01B13/32; C01B13/326; C01B21/00; C01B21/06; C01B32/00; C01B32/90; C01F; C01F7/00; C01F7/02; C01F7/42; C01F7/422; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/51; C01P2004/60; C01P2004/61

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 80 words
A method for the production of minute metal powder, which comprises imparting ultrasonic vibration to a molten metal, introducing into the ultrasonically vibrated melt a gas thereby causing said gas to be uniformly dispersed in said melt in the form of minute bubbles, allowing cavitation to occur as soon as said minute bubbles rise up said melt and reach the surface of said melt, thereby inducing conversion of said melt into minute droplets, and solidifying said minute droplets by cooling.
Claim 2
Independent Claim 80 words
A method for the production of minute metal powder, which comprises imparting ultrasonic vibration to a molten metal, introducing into the ultrasonically vibrated melt a gas thereby causing said gas to be uniformly dispersed in said melt in the form of minute bubbles, allowing cavitation to occur as soon as said minute bubbles rise up said melt and reach the surface of said melt, thereby inducing conversion of said melt into minute droplets, and solidifying said minute droplets by cooling.
Claim 3
Dependent Claim 35 words
A method according to claim 1, wherein said melt is allowed to react with a reactive gas thereby producing minute droplets of a metal compound, and subsequently solidifying said minute metal compound droplets by cooling.
Claim 4
Dependent Claim 19 words
The melthod of claim 2, wherein said gas is selected from the group consisting of oxygen, nitrogen and propane.
Claim 5
Dependent Claim 23 words
A method according to claim 1, wherein said metal is one member selected from the group consisting of elementary metals and alloys thereof.
Claim 6
Dependent Claim 15 words
The method of claim 1, wherein said gas is incapable of reacting with said melt.
Claim 7
Dependent Claim 12 words
The method of claim 5, wherein said gas is argon or hydrogen.
Claim 8
Independent Claim 128 words
An apparatus for the production of minute metal powder, which comprises a metal melting tank, means disposed contiguously to said metal melting tank and adapted to forward a metal to be melted to said metal melting tank, means for forwarding a gas into the molten metal in said metal melting tank, an ultrasonic vibration generating device adapted to impart ultrasonic vibration to the melt in said metal melting tank, and means for detecting a position of the surface of said melt in said melt in a prescribed range in said metal melting tank based on the results of the detection obtained by said detection means, and means for solidifying minute droplets of said melt issuing from the surface of said melt in said metal melting tank by cooling.
Claim 9
Independent Claim 128 words
An apparatus for the production of minute metal powder, which comprises a metal melting tank, means disposed contiguously to said metal melting tank and adapted to forward a metal to be melted to said metal melting tank, means for forwarding a gas into the molten metal in said metal melting tank, an ultrasonic vibration generating device adapted to impart ultrasonic vibration to the melt in said metal melting tank, and means for detecting a position of the surface of said melt in said melt in a prescribed range in said metal melting tank based on the results of the detection obtained by said detection means, and means for solidifying minute droplets of said melt issuing from the surface of said melt in said metal melting tank by cooling.
Claim 10
Dependent Claim 22 words
An apparatus according to claim 7, which further comprises means for issuing a gas for contact with said minute droplets of melt.
Claim 11
Dependent Claim 15 words
The apparatus of claim 8, wherein said gas is capable of reacting with said melt.
Claim 12
Dependent Claim 58 words
An apparatus according to claim 7, wherein said device for detecting the position of the surface of said melt in said metal melting tank is a means composed of electrode chips disposed inside said metal melting tank and connected electrically to drive switch of said means for forwarding a metal to be melted to said metal melting tank.

References Cited (Backward Citations)

US2997245A Cited
US3599319A Cited
US4321086A Cited
US4441542A Cited
US4522577A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-06-08 1990-12-08 1991-06-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-06-08 1994-12-08 1995-06-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-06-08 1998-12-08 1999-06-09 $7700.00 Window Closed / Lapsed

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