Patent US3017850A successfully refreshed from Google Patents.
Patent US3765929A successfully refreshed from Google Patents.
US3765929A
Expired / Lapsed
US
⏱️ 0.0 years remaining
In situ fluorination of graphite in iron alloy
Assignee: International Business Machines Corp
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Filing: 1972-03-31
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Granted: 1973-10-16
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Expires: 1992-03-31
Abstract
Abstract A self lubricating bearing surface is formed on high carbon iron alloy parts by fluorinating the exposed carbon particles at the surface of the part to form carbon monofluoride. The part is fluorinated in a reaction chamber by exposure to fluorine gas not exceeding a partial pressure of 76 torr in an inert gas and a temperature not exceeding 700* centigrade to substantially completely convert all exposed carbon particles to carbon monofluoride.
Inventors
- 👤 J Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:25
CPC Classifications
F; F16; F16C; F16C33/00; F16C33/02; F16C33/04; F16C33/06; F16C33/14; C; C01; C01B; C01B32/00; C01B32/10; C23; C23C; C23C8/00; C23C8/06; F16C2220/00; F16C2220/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
28 words
The method of claim 1 further comprising slowly heating said chamber to a temperature in excess of 100* centigrade during said purging step to induce vaporization of moisture.
Claim 2
Dependent Claim
18 words
The method of claim 2 wherein the inert gas utilized during said purging and fluorinating steps is helium.
Claim 3
Dependent Claim
18 words
The method of claim 2 wherein the inert gas utilized during said purging and fluorinating steps is nitrogen.
Claim 4
Dependent Claim
35 words
The method of claim 2 further comprising the step of rinsing said part in a mild alkaline solution after said carbon particles exposed at the part surface have been substantially completely converted to carbon monofluoride.
Claim 5
Dependent Claim
27 words
The method of claim 5 further comprising the step of drying said part following the rinsing thereof and applying a water replacing oil to the surface thereof.
Claim 6
Dependent Claim
28 words
The method of claim 6 wherein said reaction chamber has a nickel surface which develops a reaction resistant nickel fluoride film thereon in the presence of fluorine gas.
Claim 7
Independent Claim
109 words
The method of forming a self-lubricating bearing surface on a high carbon iron alloy part comprising placing said part in a reaction chamber that is resistant to fluorine gas; purging said reaction chamber with an inert gas while slowly raising the temperature of said chamber to an excess of 100* centigrade to remove substantially all moisture and oxygen therefrom; and introducing fluorine gas at a partial pressure not exceeding 10 percent of the total pressure in an inert gas into said reaction chamber while not exceeding a temperature of 700* centigrade until the carbon particles exposed at the surface of said part are substantially completely converted to carbon monofluoride.
Claim 8
Dependent Claim
11 words
The method of claim 8 wherein said inert gas is helium.
Claim 9
Dependent Claim
11 words
The method of claim 8 wherein said inert gas is nitrogen.
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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |