Patent US4402905A successfully refreshed from Google Patents.
US4402905A
Expired / Lapsed
US
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Production of a polycrystalline silicon aluminum alloy by a hot pressing technique
Assignee: Westinghouse Electric Corp
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Filing: 1982-03-05
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Granted: 1983-09-06
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Expires: 2002-03-05
Abstract
Abstract The present invention is directed to a process for preparing a body of polycrystalline silicon doped with aluminum comprising melting a mixture of silicon powder and aluminum powder, rapidly quenching the melt, grinding the solidified silicon-aluminum alloy and hot pressing to form a compact.
Inventors
- 👤 Michael A. Burke
- 👤 Robert E. Gainer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:59
CPC Classifications
C; C22; C22C; C22C29/00; C22C29/18; B; B22; B22F; B22F3/00; B22F3/12; B22F3/14; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/645
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
113 words
A process for forming a hot pressed member comprised of polysilicon and aluminum, consisting of: forming an admixture of powdered silicon and aluminum, said admixture consisting of from 2% to 8%, by weight aluminum, remainder silicon, melting said powder admixture, rapidly quenching said melt at a rate of the order of 10 6 ° C. per second, to form a solid, grinding said solid to a powder having fragment sizes up to 30 mesh and hot pressing said powder, at a temperature of from 1350° C. to 1450° C. and at a pressure of from 3750 psi to 4250 psi, into a predetermined shape having a density equal to 90% of theoritical density.
Claim 2
Dependent Claim
113 words
A process for forming a hot pressed member comprised of polysilicon and aluminum, consisting of: forming an admixture of powdered silicon and aluminum, said admixture consisting of from 2% to 8%, by weight aluminum, remainder silicon, melting said powder admixture, rapidly quenching said melt at a rate of the order of 10 6 ° C. per second, to form a solid, grinding said solid to a powder having fragment sizes up to 30 mesh and hot pressing said powder, at a temperature of from 1350° C. to 1450° C. and at a pressure of from 3750 psi to 4250 psi, into a predetermined shape having a density equal to 90% of theoritical density.
Claim 3
Dependent Claim
26 words
The process of claim 1 in which the hot pressing is carried out at a temperature of 1400° C. and 4000 psi for about 40 minutes.
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) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |