US5597625A
Expired / Lapsed
US
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Low pressure growth of cubic boron nitride films
Assignee: California Institute of Technology
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Filing: 1995-10-03
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Granted: 1997-01-28
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Expires: 2015-10-03
Abstract
Abstract A method for forming thin films of cubic boron nitride on substrates at low pressures and temperatures. A substrate is first coated with polycrystalline diamond to provide a uniform surface upon which cubic boron nitride can be deposited by chemical vapor deposition. The cubic boron nitride film is useful as a substitute for diamond coatings for a variety of applications in which diamond is not suitable. any tetragonal or hexagonal boron nitride. The cubic boron nitride produced in accordance with the preceding example is particularly well-suited for use as a coating for ultra hard tool bits and abrasives, especially those intended to use in cutting or otherwise fabricating iron.
Inventors
- 👤 Tiong P. Ong
- 👤 Yuh-Han Shing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:29
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/02; C23C16/0227; C23C16/0272; C23C16/22; C23C16/26; C23C16/27; C23C16/271; C23C16/30; C23C16/34; C23C16/342; C23C28/00; C23C28/04; C23C28/044; C23C30/00; C23C30/005; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/30
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
143 words
A method for making a tool comprising the steps of: providing a tool having a tungsten carbide cutting surface; etching said tungsten carbide cutting surface to form an acid etched surface; rubbing said acid etched surface with sub-micron diamond powder to form a diamond powder treated surface; depositing amorphous silicon onto said diamond powder treated surface to form a layer of amorphous silicon thereon; depositing a sufficient amount of diamond onto said amorphous silicon layer on said tungsten carbide cutting surface by chemical vapor deposition to form a substantially continuous polycrystalline diamond interlayer which covers said tungsten carbide cutting surface; and depositing boron nitride onto said polycrystalline diamond interlayer by chemical vapor deposition at a temperature of between 400° C. and 1000° C. and a pressure of up to 100 Torr to form a polycrystalline coating which consists essentially of cubic boron nitride.
Claim 2
Independent Claim
143 words
A method for making a tool comprising the steps of: providing a tool having a tungsten carbide cutting surface; etching said tungsten carbide cutting surface to form an acid etched surface; rubbing said acid etched surface with sub-micron diamond powder to form a diamond powder treated surface; depositing amorphous silicon onto said diamond powder treated surface to form a layer of amorphous silicon thereon; depositing a sufficient amount of diamond onto said amorphous silicon layer on said tungsten carbide cutting surface by chemical vapor deposition to form a substantially continuous polycrystalline diamond interlayer which covers said tungsten carbide cutting surface; and depositing boron nitride onto said polycrystalline diamond interlayer by chemical vapor deposition at a temperature of between 400° C. and 1000° C. and a pressure of up to 100 Torr to form a polycrystalline coating which consists essentially of cubic boron nitride.
Claim 3
Dependent Claim
36 words
A method for making a tool according to claim 1 wherein a sufficient amount of boron nitride is deposited to form a polycrystalline cubic boron nitride coating having a thickness between about 5 to 20 microns.
Claim 4
Dependent Claim
37 words
A method for making a tool according to claim 1 wherein the step of forming said polycrystalline diamond interlayer is carried out so as to form diamond crystals having crystal sizes of between 1 to 10 microns.
Claim 5
Dependent Claim
41 words
A method for making a tool according to claim 1 wherein the step of forming said polycrystalline cubic boron nitride coating is carried out so as to form cubic boron nitride crystals having crystal sizes of between 1 to 10 microns.
Claim 6
Dependent Claim
41 words
A method for making a tool according to claim 3 wherein the step of forming said polycrystalline cubic boron nitride coating is carried out so as to form cubic boron nitride crystals having crystal sizes of between 1 to 10 microns.
Claim 7
Independent Claim
133 words
A method for making a tool comprising the steps of: providing a tool having a tungsten carbide cutting surface; etching said tungsten carbide cutting surface with nitric acid; depositing by chemical vapor deposition a thin buffer layer of amorphous silicon onto said etched tungsten carbide cutting surface; depositing a sufficient amount of diamond onto said buffer layer of material by electron cyclotron resonance microwave plasma enhanced chemical vapor deposition to form a substantially continuous polycrystalline diamond interlayer which covers said buffer layer of material; and depositing boron nitride onto said polycrystalline diamond interlayer by electron cyclotron resonance microwave plasma enhanced chemical vapor deposition at a temperature of between 400° C. and 1000° C. and a pressure of up to 100 Torr to form a polycrystalline coating which consists essentially of cubic boron nitride.
Claim 8
Independent Claim
133 words
A method for making a tool comprising the steps of: providing a tool having a tungsten carbide cutting surface; etching said tungsten carbide cutting surface with nitric acid; depositing by chemical vapor deposition a thin buffer layer of amorphous silicon onto said etched tungsten carbide cutting surface; depositing a sufficient amount of diamond onto said buffer layer of material by electron cyclotron resonance microwave plasma enhanced chemical vapor deposition to form a substantially continuous polycrystalline diamond interlayer which covers said buffer layer of material; and depositing boron nitride onto said polycrystalline diamond interlayer by electron cyclotron resonance microwave plasma enhanced chemical vapor deposition at a temperature of between 400° C. and 1000° C. and a pressure of up to 100 Torr to form a polycrystalline coating which consists essentially of cubic boron nitride.
Claim 9
Dependent Claim
37 words
A method for making a tool according to claim 6 wherein a sufficient amount of boron nitride is deposited to form a polycrystalline cubic boron nitride coating having a thickness of between about 5 to 20 microns.
Claim 10
Dependent Claim
37 words
A method for making a tool according to claim 6 wherein the step of forming said polycrystalline diamond interlayer is carried out so as to form diamond crystals having crystal sizes of between 1 to 10 microns.
Claim 11
Dependent Claim
41 words
A method for making a tool according to claim 6 wherein the step of forming said polycrystalline cubic boron nitride coating is carried out so as to form cubic boron nitride crystals having crystal sizes of between 1 to 10 microns.
Claim 12
Dependent Claim
41 words
A method for making a tool according to claim 6 wherein the step of forming said polycrystalline cubic boron nitride coating is carried out so as to form cubic boron nitride crystals having crystal sizes of between 1 to 10 microns.
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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) | 2000-01-28 | 2000-07-29 | 2001-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-28 | 2004-07-29 | 2005-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-28 | 2008-07-29 | 2009-01-28 | $7700.00 | Window Closed / Lapsed |