US4029475A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blank for rolling and forging and method of producing same
Assignee: Hamai Industries Ltd
•
Filing: 1974-12-12
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Granted: 1977-06-14
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Expires: 1994-12-12
Abstract
Abstract Sintered blanks for rolling and forging, metal powders used in making such blanks, and a method of producing such blanks and powders characterized in that a compound of an alkali metal or an alkaline earth metal is added to the metal powders before sintering.
Inventors
- 👤 Yoshihiko Hamai
- 👤 Tatsuro Hamai
- 👤 Yuya Tanaka
- 👤 Akira Nakatani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:52
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/04; C22C1/0425; B; B22; B22F; B22F1/00; B22F1/16; B22F3/00; B22F3/10; B22F3/1003
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
150 words
The method of making a sintered compact which comprises the steps of adding to the initial metal powder consisting principally of copper and zinc at least one compound containing an additive metal selected from the group consisting of alkali metals and alkaline earth metals, and thereby producing a mixture consisting essentially of said at least one compound, copper and zinc, annealing said mixture at a temperature higher than the decomposition temperature of said compound, and then compacting and sintering said mixture, said at least one compound being of a type which decomposes into at least one gas which has no corrosive effect on said initial metal power, together with at least one substance selected from the group consisting of said additive metals and their oxides which substance forms a coating on said initial metal powder during said annealing step which inhibits subsequent volatalization of said zinc during said sintering step.
Claim 2
Independent Claim
150 words
The method of making a sintered compact which comprises the steps of adding to the initial metal powder consisting principally of copper and zinc at least one compound containing an additive metal selected from the group consisting of alkali metals and alkaline earth metals, and thereby producing a mixture consisting essentially of said at least one compound, copper and zinc, annealing said mixture at a temperature higher than the decomposition temperature of said compound, and then compacting and sintering said mixture, said at least one compound being of a type which decomposes into at least one gas which has no corrosive effect on said initial metal power, together with at least one substance selected from the group consisting of said additive metals and their oxides which substance forms a coating on said initial metal powder during said annealing step which inhibits subsequent volatalization of said zinc during said sintering step.
Claim 3
Dependent Claim
25 words
The method of claim 1, wherein said compound is selected from the group consisting of carbonates, oxalates, acetates, halides and silicofluorides of said additive metals.
Claim 4
Dependent Claim
20 words
The method of claim 1, wherein the copper and zinc powder has a particle size of less than 50 mesh.
Claim 5
Dependent Claim
38 words
The method claimed in claim 1 in which said powder contains at least 35% zinc, and said compound is added in an amount such that the metal in said compound constitutes about 0.1% by weight of total metal.
Claim 6
Dependent Claim
18 words
The method claimed in claim 1 which comprises the further step of compacting and forging said sintered mixture.
Claim 7
Dependent Claim
18 words
The method claimed in claim 1 which comprises the further step of compacting and rolling said sintered mixture.
Claim 8
Dependent Claim
22 words
The method claimed in claim 1 in which said compound is selected from the group consisting of salts of said additive metals.
Claim 9
Dependent Claim
11 words
A sintered compact made by the method claimed in claim 1.
Claim 10
Dependent Claim
17 words
A sintered compact as claimed in claim 8 which has been forged to form a finished article.
References Cited (Backward Citations)
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Cited
US2846339A
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US3082084A
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US3401033A
Cited
GB1013932A
Cited
US3223523A
Cited
US3386814A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-13 | 1980-12-13 | 1981-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-13 | 1984-12-13 | 1985-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-13 | 1988-12-13 | 1989-06-14 | $7700.00 | Window Closed / Lapsed |