US4927461A
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Machinable-grade, ferrous powder blend containing boron nitride and method thereof
Assignee: Quebec Metal Powders Ltd
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Filing: 1988-11-02
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Granted: 1990-05-22
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Expires: 2008-11-02
Abstract
Abstract The machinability characteristics of P/M ferrous sintered compacts are improved when the compact is prepared from a ferrous powder having a maximum particle size less than about 300 microns, and from at least about 0.01 weight percent of a boron nitride powder comprising agglomerates of irregular-shaped, submicron particles.
Inventors
- 👤 Cavit Ciloglu
- 👤 Martin Gagne
- 👤 Edy Laraque
- 👤 Joel Poirier
- 👤 Sylvain Tremblay
- 👤 Yves Trudel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:45
CPC Classifications
B; B22; B22F; B22F1/00; C; C22; C22C; C22C33/00; C22C33/02; C22C33/0207; C22C33/0228; B22F3/00; B22F3/10; B22F3/1003
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
51 words
A powder metallurgy blend comprising: from about 85 to about 99.99 weight percent of a ferrous powder having a maximum particle size of less than about 300 microns; and from about 0.0I to about 0 5 weight percent boron nitride powder comprising irregularly-shaped submicron particles of about 1 micron or less.
Claim 2
Dependent Claim
51 words
A powder metallurgy blend comprising: from about 85 to about 99.99 weight percent of a ferrous powder having a maximum particle size of less than about 300 microns; and from about 0.0I to about 0 5 weight percent boron nitride powder comprising irregularly-shaped submicron particles of about 1 micron or less.
Claim 3
Dependent Claim
21 words
The powder blend of claim 1 where the maximum particle size of the ferrous powder is less than about 212 microns.
Claim 4
Dependent Claim
19 words
The powder blend of 1 where the ferrous powder comprises at least about 90 weight percent of the blend.
Claim 5
Dependent Claim
19 words
The powder blend of 1 where the ferrous powder comprises at least about 90 weight percent of the blend.
Claim 6
Dependent Claim
20 words
The powder blend of claim 1 where the boron nitride comprises at least about 0.02 weight percent of the blend.
Claim 7
Dependent Claim
22 words
The powder blend of claim 3 where the boron nitride powder comprises between about 0.02 and 0.1 weight percent of the blend.
Claim 8
Dependent Claim
20 words
The powder blend of claim 5 where the boron nitride powder contains less than about 5 weight percent boric oxide.
Claim 9
Dependent Claim
20 words
The powder blend of claim 5 where the boron nitride powder contains less than about 3 weight percent boric oxide.
Claim 10
Dependent Claim
24 words
The powder blend of claim 7 where the submicron particles of boron nitride have an average particle size between about 0.05 and 1.0 micron.
Claim 11
Dependent Claim
24 words
The powder blend of claim 8 where the submicron particles of boron nitride have an average particle size between about 0.1 and 1 micron.
Claim 12
Dependent Claim
15 words
A ferrous shape made from compacting the powder blend of claim any of claims 1-9.
Claim 13
Dependent Claim
26 words
The powder blend of any of claims 2-5, where the submicron particles of boron nitride have an average particle size between about 0.2 and 1 micron.
Claim 14
Dependent Claim
22 words
The powder blend of claim 11 where the boron nitride powder comprises between about 0.03 and 0.07 weight percent of the blend.
Claim 15
Dependent Claim
16 words
The powder blend of any of claims 1-3, where the ferrous powder is a steel powder
Claim 16
Dependent Claim
15 words
The powder blend of claim 13, where said steel powder is a stainless steel powder.
Claim 17
Dependent Claim
25 words
The powder blend of any of claims 1-5, further comprising at least one alloying powder selected from the group consisting of graphite, copper and nickel.
Claim 18
Dependent Claim
93 words
A process for producing a powder composition for use in fabricating a ferrous part, comprising the steps of: selecting a ferrous powder having a maximum particle size of less than about 300 microns; selecting a boron nitride powder comprising irregularly-shaped submicron particles of less than about 1 micron; and blending said boron nitride powder with the ferrous powder to make a mixture of said powders, said mixture comprising from about 85 to about 99.99 weight percent of ferrous powder and from about 0.01 to about 0.5 weight percent of said boron nitride powder.
Claim 19
Dependent Claim
93 words
A process for producing a powder composition for use in fabricating a ferrous part, comprising the steps of: selecting a ferrous powder having a maximum particle size of less than about 300 microns; selecting a boron nitride powder comprising irregularly-shaped submicron particles of less than about 1 micron; and blending said boron nitride powder with the ferrous powder to make a mixture of said powders, said mixture comprising from about 85 to about 99.99 weight percent of ferrous powder and from about 0.01 to about 0.5 weight percent of said boron nitride powder.
Claim 20
Dependent Claim
26 words
The process for producing a powder composition of claim 16, including the step of selecting agglomerates of said boron nitride particles as said boron nitride powder.
Claim 21
Dependent Claim
25 words
A process for producing a powder composition of claim 17, wherein said boron nitride powder particle agglomerates are from about 5 to about 50 microns.
Claim 22
Dependent Claim
19 words
A process for producing a powder composition of claim 18, wherein the agglomerates are less than about 30 microns.
Claim 23
Dependent Claim
73 words
An improved process for fabricating a ferrous part by applying pressure to a ferrous powder within a cavity, the improvement comprising: utilizing as said mixture a composition comprising from about 85 to about 99.99 weight percent of a ferrous powder having a maximum particle size less than about 300 microns and from about 0.01 to about 0.5 weight percent of a boron nitride powder comprising irregularly-shaped particles of less than about 1 micron.
Claim 24
Dependent Claim
73 words
An improved process for fabricating a ferrous part by applying pressure to a ferrous powder within a cavity, the improvement comprising: utilizing as said mixture a composition comprising from about 85 to about 99.99 weight percent of a ferrous powder having a maximum particle size less than about 300 microns and from about 0.01 to about 0.5 weight percent of a boron nitride powder comprising irregularly-shaped particles of less than about 1 micron.
Claim 25
Independent Claim
96 words
A method for improving the machinability of powder metallurgy using boron nitride, comprising the steps of: selecting a boron nitride powder comprising irregularly-shaped particles of less than about 1 micron; selecting a ferrous powder having a maximum particle size less than about 300 microns; blending said boron nitride powder with the ferrous powder to make a mixture of said powders, said mixture comprising from about 85 to about 99.99 weight percent of ferrous powder and from about 0.01 to about 0.5 weight percent of said boron nitride powder; and producing a sintered compact of said mixture.
Claim 26
Independent Claim
96 words
A method for improving the machinability of powder metallurgy using boron nitride, comprising the steps of: selecting a boron nitride powder comprising irregularly-shaped particles of less than about 1 micron; selecting a ferrous powder having a maximum particle size less than about 300 microns; blending said boron nitride powder with the ferrous powder to make a mixture of said powders, said mixture comprising from about 85 to about 99.99 weight percent of ferrous powder and from about 0.01 to about 0.5 weight percent of said boron nitride powder; and producing a sintered compact of said mixture.
Claim 27
Dependent Claim
28 words
A method of improving the machinability of powder metallurgy of claim 20, including the step of selecting agglomerates of said boron nitride particles as said boron nitride powder.
Claim 28
Dependent Claim
27 words
A method for improving the machinability of powder metallurgy of claim 21, wherein said boron nitride powder particle agglomerates are from about 5 to about 50 microns.
Claim 29
Dependent Claim
21 words
A method for improving the machinability of powder metallurgy of claim 23, wherein the agglomerates are less than about 30 microns.
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) | 1993-05-21 | 1993-11-20 | 1994-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-21 | 1997-11-20 | 1998-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-21 | 2001-11-20 | 2002-05-22 | $7700.00 | Window Closed / Lapsed |