Patent US4230494A successfully refreshed from Google Patents.
US4230494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Article highly resistant to corrosion by gallium phosphide and gallium arsenide
Assignee: Toshiba Corp
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Filing: 1978-07-13
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Granted: 1980-10-28
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Expires: 1998-07-13
Abstract
Abstract An article has a portion contacted by gallium phosphide or gallium arsenide. At least the contacting portion is formed of a sintered body of a mixture of silicon nitride and an additive, and part or the whole of the additive is present as a crystallized phase in the sintered silicon nitride system.
Inventors
- 👤 Kiyoshi Nakamura
- 👤 Michiyasu Komatsu
- 👤 Masae Nakanishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:11
CPC Classifications
C; C30; C30B; C30B15/00; C30B15/20; C30B15/22; C30B15/24; C30B27/00; C30B27/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
122 words
An article having at least a portion which directly contacts molten gallium phosphide or gallium arsenide, said contacting portion comprising: a sintered body of silicon nitride and a total of from 0.5% to 20% by weight, based on said silicon nitride, of an additive selected from the group consisting of 0.01% to 10% by weight based on said silicon nitride, of aluminum oxide, 0.5% to 20% by weight, based on said silicon nitride, of cerium oxide and mixtures thereof, said additive being in the form of a compound selected from the group consisting of Si-Ce-O-N, Si-Ce-Al-O-N and mixtures thereof depending upon the additive selected, and at least a portion of said additive being present in said sintered body as a crystallized phase.
Claim 2
Dependent Claim
122 words
An article having at least a portion which directly contacts molten gallium phosphide or gallium arsenide, said contacting portion comprising: a sintered body of silicon nitride and a total of from 0.5% to 20% by weight, based on said silicon nitride, of an additive selected from the group consisting of 0.01% to 10% by weight based on said silicon nitride, of aluminum oxide, 0.5% to 20% by weight, based on said silicon nitride, of cerium oxide and mixtures thereof, said additive being in the form of a compound selected from the group consisting of Si-Ce-O-N, Si-Ce-Al-O-N and mixtures thereof depending upon the additive selected, and at least a portion of said additive being present in said sintered body as a crystallized phase.
Claim 3
Dependent Claim
25 words
The article according to claim 1, wherein said silicon nitride phase is a mixture of α'-Si 3 N 4 and β'-Si 3 N 4 .
Claim 4
Dependent Claim
21 words
The article according to claim 1, wherein the sintered body is formed of a phase of α'-Si 3 N 4 .
Claim 5
Dependent Claim
21 words
The article according to claim 1, wherein the sintered body is formed of a phase of β'-Si 3 N 4 .
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) | 1983-10-28 | 1984-04-28 | 1984-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-28 | 1988-04-28 | 1988-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-28 | 1992-04-28 | 1992-10-28 | $7700.00 | Window Closed / Lapsed |