Patent US4557244A successfully refreshed from Google Patents.
US4557244A
Expired / Lapsed
US
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Method of machine cutting silicon metal particulates with Si3 N4
Assignee: Ford Motor Co
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Filing: 1984-04-13
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Granted: 1985-12-10
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Expires: 2004-04-13
Abstract
Abstract A method is disclosed of machine cutting a semidense silicon comprising particulate body by relatively moving a substantially fully dense silicon nitride cutting tool against the body. The silicon nitride tool experiences increased tool life over that of carbides or tool steels heretofore used to machine cut low density, highly abrasive metals.
Inventors
- 👤 Richard L. Allor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:53
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593; B; B28; B28D; B28D5/00; Y; Y10; Y10T; Y10T409/00; Y10T409/30; Y10T409/303752
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
41 words
A process of machine cutting a semidense polycrystalline silicon comprising particulate body by relatively moving a substantially fully dense silicon nitride cutting tool against said semidense silicon comprising particulate body to shear off portions of said body along a predetermined path.
Claim 2
Dependent Claim
41 words
A process of machine cutting a semidense polycrystalline silicon comprising particulate body by relatively moving a substantially fully dense silicon nitride cutting tool against said semidense silicon comprising particulate body to shear off portions of said body along a predetermined path.
Claim 3
Dependent Claim
43 words
The process of machine cutting as in claim 1, in which the density of said semidense silicon comprising particulate body is in the range of 1.0-1.9 gm/cm 3 and said cutting tool has a density in the range of 3.20-3.29 gm/cm 3 .
Claim 4
Dependent Claim
26 words
The process of machine cutting as in claim 1, in which the path sheared by said tool has a cross-sectional area of at least 0.01 inch.
Claim 5
Dependent Claim
61 words
The process of machine cutting as in claim 1, in which said relative movement of said cutting tool is carried out by using said tool to cut deep grooves in said silicon comprising particulate body to define sub-bodies, leaving only enough ungrooved material between said sub-bodies to define hinges therebetween of sufficient structural strength to admit subsequent densification and eventual severance.
Claim 6
Dependent Claim
29 words
The process of machine cutting as in claim 4, in which said deep grooves are cut in a grid pattern penetrating to a depth of 90-95% of said body.
Claim 7
Dependent Claim
24 words
The process of machine cutting as in claim 1, in which said shearing separates the silicon from said body as a powder or chips.
Claim 8
Dependent Claim
38 words
The process of machine cutting as in claim 1, in which said silicon nitride tool is comprised of a material having a hardness of 86-92 on the 45-N scale and has a density of 3.2-3.29 gm/cm 3 .
Claim 9
Dependent Claim
34 words
The process of machine cutting as in claim 1, in which the difference in density between said silicon comprising particulate body and said silicon nitride cutting tool is at least 1.0 gm/cm 3 .
Claim 10
Dependent Claim
27 words
The process of machine cutting as in claim 1, in which said cutting tool is shaped as a milling tool, a turning tool, or a grooving tool.
Claim 11
Dependent Claim
50 words
The process of machine cutting as in claim 4, in which said silicon comprising particulate body is shaped as a disc having a thickness of about 0.3-0.8 inch and opposed faces with a diameter of about 3-12 inches, said grooves being cut in one of said faces of said body.
Claim 12
Dependent Claim
25 words
The process of machine cutting as in claim 1, in which the semidense silicon comprising particulate body is polycrystalline with discrete silicon particles agglomerated together.
Claim 13
Dependent Claim
53 words
The process of machine cutting as in claim 1, in which said silicon comprising particulate body is comprised of nonreacted heat agglomerated silicon powder and oxygen carrying powder agents, the oxygen carrying powder agents being present in an amount so that upon nitriding the mixture will consist essentially of silicon nitride and oxynitrides.
Claim 14
Dependent Claim
45 words
The process of machine cutting as in claim 12, in which the oxygen carrying agents comprise 4-12% Y 2 O 3 and 0.5-5.0% Al 2 O 3 , the oxygen carrying agents, when reacted, form a Si 3 N 4 object with about 2-14% oxynitrides.
Claim 15
Dependent Claim
35 words
The process of machine cutting as in claim 1, in which said body to be cut is presintered and is made up essentially, by weight, of silicon powder with up to 3% SiO 2 .
Claim 16
Dependent Claim
48 words
The process of machine cutting as in claim 1, in which said body to be cut is prenitrided and is made up essentially of, by weight, about 15% Si 3 N 4 , up to 3% SiO 2 , up to 20% silicon compounds, and the remainder silicon.
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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) | 1988-12-09 | 1989-06-10 | 1989-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-09 | 1993-06-10 | 1993-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-09 | 1997-06-10 | 1997-12-10 | $7700.00 | Window Closed / Lapsed |