US5194128A
Expired / Lapsed
US
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Method for manufacturing ultrafine particles
Assignee: Leidos Security Detection and Automation Inc
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Filing: 1991-08-02
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Granted: 1993-03-16
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Expires: 2011-08-02
Abstract
Abstract A method for the manufacture of ultrafine particles or atom clusters is disclosed. The ultrafine particles of size between about 10 to 1000 Angstroms are formed by the disruption of the crystal lattice or micrograin structure of the metal, alloy or intermetallic compound in one or both of two spaced electrodes by a high frequency, high voltage, high peak current discharge. The ultrafine particles are not subjected to fractionation as in evaporative processes and accordingly are remarkably predictable in both particle size, distribution of sizes and atomic composition, and also are readily transportable in carrier gases.
Inventors
- 👤 John S. Beaty
- 👤 Jonathan L. Rolfe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:35
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/14
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
63 words
A method of manufacturing non-vaporized ultrafine particles comprising: providing two electrodes each containing a conductive material; mounting said electrodes in spaced-apart relationship in a reaction chamber; repetitively producing a spark between the electrodes to cause non-vaporizing ablation of at least one of the electrodes and formation of ultrafine particles; and carrying said ablated material away from the reaction chamber in a carrier gas.
Claim 2
Independent Claim
63 words
A method of manufacturing non-vaporized ultrafine particles comprising: providing two electrodes each containing a conductive material; mounting said electrodes in spaced-apart relationship in a reaction chamber; repetitively producing a spark between the electrodes to cause non-vaporizing ablation of at least one of the electrodes and formation of ultrafine particles; and carrying said ablated material away from the reaction chamber in a carrier gas.
Claim 3
Dependent Claim
35 words
The method of claim 1 including operating the spark source at a voltage of between about 14000 and 20000 volts sinking to a voltage between about 10 and 100 volts during conduction between the electrodes.
Claim 4
Dependent Claim
57 words
The method according to claim 1 wherein the electrode-providing step comprises providing a first electrode containing a material to be ablated and providing a second electrode of an erosion-resistant material, and including operating said spark source to produce a rectified current waveform having positive oscillatory currents only so as to ablate material only from said first electrode.
Claim 5
Dependent Claim
33 words
The method of claim 3 wherein said first electrode contains at least two materials; such that said step of repetitively producing a spark between the electrodes causes non-fractionating ablation of said first electrode.
Claim 6
Dependent Claim
38 words
The method of claim 1 wherein the reaction chamber is supplied with a carrier gas at a pressure of from 100 to 1000 millibars, and carrying said ablated material away from the reaction chamber in said carrier gas.
Claim 7
Dependent Claim
54 words
The method of claim 1 wherein the electrode providing step comprises providing as at least one of said electrodes, an electrode containing at least two materials; such that said step of repetitively producing a spark between the electrodes causes non-fractionating ablation of at least one of the electrodes and formation of non-fractionated ultrafine particles.
Claim 8
Independent Claim
115 words
A method of manufacturing non-vaporized ultrafine particles of a specific compound comprising: providing a first conductive electrode including a first material which is a constituent of said compound and a second conductive electrode including a second material which is a constituent of said compound; mounting said electrodes in spaced-apart relationship in a reaction chamber; operating said spark source in a manner to repetitively produce a spark between the electrodes to cause non-vaporizing ablation of portions of said electrodes to yield ultrafine particles of said constituents; allowing said constituents to react to form ultrafine particles of said compound; and carrying said non-fractionated ultrafine particles of said compound away from said reaction chamber in a carrier gas.
Claim 9
Independent Claim
115 words
A method of manufacturing non-vaporized ultrafine particles of a specific compound comprising: providing a first conductive electrode including a first material which is a constituent of said compound and a second conductive electrode including a second material which is a constituent of said compound; mounting said electrodes in spaced-apart relationship in a reaction chamber; operating said spark source in a manner to repetitively produce a spark between the electrodes to cause non-vaporizing ablation of portions of said electrodes to yield ultrafine particles of said constituents; allowing said constituents to react to form ultrafine particles of said compound; and carrying said non-fractionated ultrafine particles of said compound away from said reaction chamber in a carrier gas.
Claim 10
Dependent Claim
71 words
The method of claim 7 wherein the electrode providing step comprises providing, as at least one of said conductive electrodes containing a constituent of said compound, an electrode which comprises at least two materials; such that said step of repetitively producing a spark between the electrode causes non-fractionating ablation of said constituent of at least two materials and formation of non-fractionated ultrafine particles of said constituent of at least two materials.
Claim 11
Independent Claim
95 words
A method of manufacturing non-vaporized ultrafine particles of a specific compound comprising: providing two electrodes each containing a conductive material; mounting said electrodes in spaced-apart relationship in a reaction chamber; repetitively producing a spark between the electrodes to cause non-vaporizing ablation of at least one of the electrodes; supplying to said reaction chamber a gas reactive with the ablated material and allowing said gas and said ablated material to react to form ultrafine particles of said specific compound; and carrying said ultrafine particles of said compound away from said reaction chamber in a carrier gas.
Claim 12
Independent Claim
95 words
A method of manufacturing non-vaporized ultrafine particles of a specific compound comprising: providing two electrodes each containing a conductive material; mounting said electrodes in spaced-apart relationship in a reaction chamber; repetitively producing a spark between the electrodes to cause non-vaporizing ablation of at least one of the electrodes; supplying to said reaction chamber a gas reactive with the ablated material and allowing said gas and said ablated material to react to form ultrafine particles of said specific compound; and carrying said ultrafine particles of said compound away from said reaction chamber in a carrier gas.
Claim 13
Dependent Claim
31 words
The method of claim 9 wherein a single gas is supplied to said reaction chamber for reacting with said ablated material and for carrying away the ultrafine particles of said compound.
Claim 14
Dependent Claim
49 words
The method of claim 9 wherein the electrode providing step comprises providing, as at least one of said conductive electrodes, an electrode containing at least two materials; such that said step of repetitively producing a spark between the electrodes causes non-fractionating ablation of at least one of the electrodes.
Claim 15
Independent Claim
127 words
A method of manufacturing and combining dual streams of non-vaporized ultrafine particles comprising: mounting a first pair of conductive electrodes in a spaced-apart relationship in a first reaction chamber; mounting a second pair of electrodes in a spaced-apart relationship in a second reaction chamber; repetitively producing a spark between each pair of electrodes to cause non-vaporizing ablation of at least one electrode of each pair and formation of ultrafine particles; supplying carrier gases to each of said reaction chambers to carry said ablated materials away from said reaction chambers as first and second gas/particles streams; and directing said first and second gas/particle streams to a single flow conduit in a controlled manner to create a blended flow, or sequential flows, of said first and second gas/particle streams.
Claim 16
Independent Claim
127 words
A method of manufacturing and combining dual streams of non-vaporized ultrafine particles comprising: mounting a first pair of conductive electrodes in a spaced-apart relationship in a first reaction chamber; mounting a second pair of electrodes in a spaced-apart relationship in a second reaction chamber; repetitively producing a spark between each pair of electrodes to cause non-vaporizing ablation of at least one electrode of each pair and formation of ultrafine particles; supplying carrier gases to each of said reaction chambers to carry said ablated materials away from said reaction chambers as first and second gas/particles streams; and directing said first and second gas/particle streams to a single flow conduit in a controlled manner to create a blended flow, or sequential flows, of said first and second gas/particle streams.
Claim 17
Dependent Claim
30 words
The method of claim 12 further including directing a dopant material to said single flow conduit to dope particles in at least one of said first and second gas/particle streams.
Claim 18
Dependent Claim
64 words
The method of claim 12 wherein the electrode mounting step comprises, as providing at least one of said conductive electrodes, an electrode containing at least two materials; such that said step of repetitively producing a spark between a pair of electrodes in which one of said pair contains at least two materials causes non-fractionating ablation of said electrode and formation of non-fractionated ultrafine particles.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-03-15 | 1996-09-14 | 1997-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-15 | 2000-09-14 | 2001-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-15 | 2004-09-14 | 2005-03-16 | $7700.00 | Window Closed / Lapsed |