US4719078A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of sintering compacts
Assignee: JFE Engineering Corp
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Filing: 1986-09-16
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Granted: 1988-01-12
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Expires: 2006-09-16
Abstract
Abstract A method of sintering compacts of metals, ceramics and the like in powder form. At least the surface portion of the compact is sintered in a plasma atmosphere having a pressure of 10 Torr or less thereby eliminating the open voids and then the compact is subjected to a hot isostatic press process.
Inventors
- 👤 Tsuneo Miyashita
- 👤 Hiroaki Nishio
- 👤 Michitaka Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:13
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/1208; B22F3/1258; B22F3/1266; C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/645; C04B35/6455
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
70 words
A method of sintering a compact produced by compressing a metal powder, ceramic power or the like comprising the steps of: pre-sintering only the surface portion of the compact by means of a plasma sintering method wherein only the surface portion of a compact is sintered and the core thereof is left unsintered; and thereafter completely sintering the entire inner portion of the compact by a hot isostatic press process.
Claim 2
Independent Claim
70 words
A method of sintering a compact produced by compressing a metal powder, ceramic power or the like comprising the steps of: pre-sintering only the surface portion of the compact by means of a plasma sintering method wherein only the surface portion of a compact is sintered and the core thereof is left unsintered; and thereafter completely sintering the entire inner portion of the compact by a hot isostatic press process.
Claim 3
Dependent Claim
26 words
A method according to claim 1, wherein volatile ingredients in said compact are removed prior to said sintering of a surface portion in a plasma atmosphere.
Claim 4
Dependent Claim
40 words
A method according to claim 1, wherein said compact contains a metal powder or powders, and wherein an inert gas alone or a mixed gas of an inert gas and a reducing gas is used as a plasma working gas.
Claim 5
Dependent Claim
34 words
A method according to claim 1, wherein said compact contains an oxidic ceramic powder or powders, and wherein an inert gas alone or an oxygen-containing inert gas is used as a plasma working gas.
Claim 6
Dependent Claim
28 words
A method according to claim 1, wherein said compact contains a nonoxidic ceramic powder or powders, and wherein a nonoxidizing gas is used as a plasma working gas.
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) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |