Patent US4955798A successfully refreshed from Google Patents.
US4955798A
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Process for pretreating metal in preparation for compacting operations
Assignee: Quebec Metal Powders Ltd
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Filing: 1989-09-27
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Granted: 1990-09-11
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Expires: 2009-09-27
Abstract
Abstract A pretreating process in powder metallurgy for preparing powders for compacting or densifying operations includes the steps of mixing powder metals with solid lubricants and optionally with liquid solvents to form a mixture and heating the resulted mixture prior to compacting or densifying to a temperature greater than room temperature and below the softening temperature of the solid lubricants.
Inventors
- 👤 Vincenzo Musella
- 👤 Mario D'Angelo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:46
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/6325; B; B22; B22F; B22F1/00; B22F1/10; B22F3/00; B22F3/02; B22F2003/023; B22F3/12; B22F3/14; B22F2003/145
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
51 words
A process for pretreating metallurgical powders in preparation for compacting or densifying comprising the steps of mixing said metallurgical powders with a solid lubricant to form a mixture heating said mixture prior to compacting or densifying to a temperature above room temperature and below the softening temperature of the solid lubricant.
Claim 2
Dependent Claim
51 words
A process for pretreating metallurgical powders in preparation for compacting or densifying comprising the steps of mixing said metallurgical powders with a solid lubricant to form a mixture heating said mixture prior to compacting or densifying to a temperature above room temperature and below the softening temperature of the solid lubricant.
Claim 3
Dependent Claim
22 words
The process according to claim 1, further including the step of mixing a liquid solvent with said mixture before the heating step.
Claim 4
Dependent Claim
18 words
The process according to claim 1, wherein said heating step occurs in the absence of a nonoxidizing atmosphere.
Claim 5
Dependent Claim
17 words
The process according to claim 1, wherein said heating step occurs in the presence of ambient air.
Claim 6
Dependent Claim
32 words
The process according to claim 1, wherein said solid lubricant has a softening temperature above 120° C. and said heating step is to a temperature above 70° C. and below 120° C.
Claim 7
Dependent Claim
31 words
The process according to claim 1, wherein said solid lubricant is a member selected from the group of lithium, zinc and other metal stearates, paraffins, waxes, natural or synthetic fat derivatives.
Claim 8
Dependent Claim
15 words
The process according to claim 2, wherein said liquid solvent is a paraffinic organic solvent.
Claim 9
Dependent Claim
13 words
The process according to claim 2, wherein said liquid solvent is lamp oil.
Claim 10
Dependent Claim
25 words
The process according to claim 1, wherein said solid lubricant is in an amount of between about 0.2 and 10% by weight of said mixture.
Claim 11
Dependent Claim
25 words
The process according to claim 2, wherein said liquid solvent is in an amount of between about 0 and 200 grams per ton of powder.
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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) | 1993-09-10 | 1994-03-12 | 1994-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-10 | 1998-03-12 | 1998-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-10 | 2002-03-12 | 2002-09-11 | $7700.00 | Window Closed / Lapsed |