US3885294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a bonded silicon nitride article having portions of different density
Assignee: Ceradyne Inc
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Filing: 1974-04-03
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Granted: 1975-05-27
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Expires: 1994-04-03
Abstract
Abstract A method of making a duo density article of silicon nitride is taught. A first article portion is formed by shaping silicon metal particles into a suitable configuration and nitriding the same. A release agent is applied to selected surfaces of the first article portion. A readily formable encapsolent, having relatively low strength, is applied to the selected surface of the first article portion. The encapsolent is converted to a high strength material. A second article portion of silicon nitride is hot press bonded to a surface of the first article portion which has no encapsolent thereon. The encapsolent is machined to remove portions thereof, the removal of such portions freeing other portions of the encapsolent to be removed as individual segments.
Inventors
- 👤 Gerald J Chaundy
- 👤 Andre Ezis
- 👤 Michael U Goodyear
- 👤 Benjamin T Howes
- 👤 Carl F Johnson
- 👤 Karsten H Styhr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:01
CPC Classifications
B; B22; B22F; B22F7/00; B22F7/06; B22F5/00; B22F5/08; C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/591; C04B35/593; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49316; Y10T29/49336; Y10T29/4981; Y10T29/49812
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
122 words
A METHOD OF MAKING A DUO DENSITY ARTICLE OF SILICON NITRIDE WHICH COMPRISES: FORMING A FIRST ARTICLE PORTION OF SILICON NITRIDE BY SHAPING SILICON METAL PARTICLES INTO A SUITABLE CONFIGURATION AND NITRIDING THE SAME; APPLYING A RELEASE AGENT TO SELECTED SURFACES OF THE FIRST ARTICLE PORTION; APPLYING AN ENCAPSOLENT WHICH IS READILY FORMABLE BUT OF RELATIVELY LOW STRENGTH TO THE SELECTED SURFACES OF THE FIRST ARTICLE PORTION; CONVERTING THE ENCAPSOLENT TO A HIGH STRENGTH MATERIAL; HOT PRESS BONDING A SECOND ARTICLE PORTION OF SILICON NITRIDE TO A SURFACE OF THE FIRST ARTICLE PORTION WHICH HAS NO ENCAPSOLENT THEREON; MACHINING THE ENCAPSOLENT TO REMOVE PORTIONS THEREOF; THE REMOVAL OF SUCH PORTIONS FREEING OTHER PORTIONS OF THE ENCAPSOLENT TO BE REMOVED AS INDIVIDUAL SEGMENTS.
Claim 2
Independent Claim
122 words
A METHOD OF MAKING A DUO DENSITY ARTICLE OF SILICON NITRIDE WHICH COMPRISES: FORMING A FIRST ARTICLE PORTION OF SILICON NITRIDE BY SHAPING SILICON METAL PARTICLES INTO A SUITABLE CONFIGURATION AND NITRIDING THE SAME; APPLYING A RELEASE AGENT TO SELECTED SURFACES OF THE FIRST ARTICLE PORTION; APPLYING AN ENCAPSOLENT WHICH IS READILY FORMABLE BUT OF RELATIVELY LOW STRENGTH TO THE SELECTED SURFACES OF THE FIRST ARTICLE PORTION; CONVERTING THE ENCAPSOLENT TO A HIGH STRENGTH MATERIAL; HOT PRESS BONDING A SECOND ARTICLE PORTION OF SILICON NITRIDE TO A SURFACE OF THE FIRST ARTICLE PORTION WHICH HAS NO ENCAPSOLENT THEREON; MACHINING THE ENCAPSOLENT TO REMOVE PORTIONS THEREOF; THE REMOVAL OF SUCH PORTIONS FREEING OTHER PORTIONS OF THE ENCAPSOLENT TO BE REMOVED AS INDIVIDUAL SEGMENTS.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein: the encapsolent is applied by applying a silicon metal particle encapsolent to the selected surfaces and then nitriding the silicon metal particle encapsolent.
Claim 4
Independent Claim
125 words
A method of making a duo density article of silicon nitirde which comprises: forming a first article portion of silicon nitride by shaping silicon metal particles into a suitable configuration and nitriding the same; applying a release agent to selected surfaces of the first article portion; applying a silicon metal particle encapsolent to the selected surfaces of the first article portion; nitriding the silicon metal particle encapsolent; hot press bonding a second article portion of silicon nitride to a surface of the first article portion which has no silicon nitride encapsolent thereon; machining the silicon nitride encapsolent to remove portions thereof, the removal of such portions freeing other portions of the encapsolent to be removed as individual segments, whereby the duo density article is produced.
Claim 5
Independent Claim
125 words
A method of making a duo density article of silicon nitirde which comprises: forming a first article portion of silicon nitride by shaping silicon metal particles into a suitable configuration and nitriding the same; applying a release agent to selected surfaces of the first article portion; applying a silicon metal particle encapsolent to the selected surfaces of the first article portion; nitriding the silicon metal particle encapsolent; hot press bonding a second article portion of silicon nitride to a surface of the first article portion which has no silicon nitride encapsolent thereon; machining the silicon nitride encapsolent to remove portions thereof, the removal of such portions freeing other portions of the encapsolent to be removed as individual segments, whereby the duo density article is produced.
Claim 6
Dependent Claim
35 words
The method of claim 3 wherein: the selected surfaces to which the release agent and the silicon metal particle encapsolent are applied are the surfaces which require support during fabrication of the duo density article.
Claim 7
Dependent Claim
17 words
The method of claim 3 wherein: the first article portion is formed by an injection molding operation.
Claim 8
Dependent Claim
17 words
The method of claim 3 wherein: the first article portion is formed by a slip casting operation.
Claim 9
Dependent Claim
18 words
The method of claim 3 wherein: the silicon metal particle encapsolent is applied by an injection molding operation.
Claim 10
Dependent Claim
17 words
The method of claim 3 wherein: the silicon metal encapsolent is applied by a slip casting operation.
Claim 11
Dependent Claim
41 words
The method of claim 3 wherein: the hot press bonding operation is carried out at a temperature of from about 1625*C to about 1700*C, at a pressure of at least 1000 psi, and for a time of at least 1.5 hours.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |