US4097274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making superhard articles
Assignee: Individual
•
Filing: 1976-05-19
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Granted: 1978-06-27
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Expires: 1996-05-19
Abstract
Abstract A superhard article is produced by heating in two steps a mixture of a hard-alloy matrix material and diamond grains less than 1 mm in size in a graphite press mould. During the first heating step, the mixture is heated to a temperature of 1,200° C at a rate of 1,000°-1,100° C per minute by heating the press mould by high frequency. During the second heating step, the mixture is heated to the sintering temperature, up to 1,800° C at a rate of 3,000°-10,000° C per minute by heating the mixture by the resistance method, i.e. by passing electric current through the mixture while simultaneously heating the press mould by high frequency currents.
Inventors
- 👤 Valentin Nikolaevich Bakul
- 👤 Igor Ivanovich Bilyk
- 👤 Dolores Khaimovna Bronshtein
- 👤 Ivan Fedorovich Vovchanovsky
- 👤 Nekhemian Veniaminovich Tsypin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:52
CPC Classifications
C; C22; C22C; C22C26/00; B; B01; B01J; B01J3/00; B01J3/06; B01J3/062; B22; B22F; B22F3/00; B22F3/10; B22F3/105; B01J2203/00; B01J2203/06; B01J2203/0605; B01J2203/062; B01J2203/065; B01J2203/0655; B01J2203/0675; B01J2203/0685
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
175 words
A method of producing a superhard article comprising the steps of: charging a mixture of diamond grains less than 1 mm in size and a hard-alloy matrix material into a graphite press mould with the diamond grains being evenly distributed throughout the hard-alloy matrix material; heating the mixture under a pressure of from 50 to 100 kg/cm 2 to 1,200° C at a rate of from 1,000° to 1,100° C per minute by passing high frequency currents through the press mould; maintaining the mixture in the press mould at 1,200° C for less than 2 minutes to preclude graphitization and dissolution of the diamond grains; heating the mixture under a pressure of from 100 to 200 kg/cm 2 to a sintering temperature less than 1,800° C at a rate of from 3,000° to 10,000° C per minute by simultaneously passing a current through the mixture and passing high frequency currents through the press mould; and maintaining the mixture in the press mould at the sintering temperature for a period of from 2 to 3 seconds.
Claim 2
Independent Claim
175 words
A method of producing a superhard article comprising the steps of: charging a mixture of diamond grains less than 1 mm in size and a hard-alloy matrix material into a graphite press mould with the diamond grains being evenly distributed throughout the hard-alloy matrix material; heating the mixture under a pressure of from 50 to 100 kg/cm 2 to 1,200° C at a rate of from 1,000° to 1,100° C per minute by passing high frequency currents through the press mould; maintaining the mixture in the press mould at 1,200° C for less than 2 minutes to preclude graphitization and dissolution of the diamond grains; heating the mixture under a pressure of from 100 to 200 kg/cm 2 to a sintering temperature less than 1,800° C at a rate of from 3,000° to 10,000° C per minute by simultaneously passing a current through the mixture and passing high frequency currents through the press mould; and maintaining the mixture in the press mould at the sintering temperature for a period of from 2 to 3 seconds.
Claim 3
Dependent Claim
30 words
The method as claimed in claim 1, wherein the mixture is heated from 1,200° C to the sintering temperature at a rate of from 3,000° to 3,100° C per minute.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |