US4797155A
Expired / Lapsed
US
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Method for making metal matrix composites
Assignee: Boeing Co
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Filing: 1987-02-27
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Granted: 1989-01-10
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Expires: 2007-02-27
Abstract
Abstract A metal matrix composite is produced by plastically deforming a metal powder, either or after blending the powder with ceramic fibers, and compacting the mixture at elevated temperatures to achieve substantially full density. Imparting strain energy to the metal allows reduction of the compaction temperature to eliminate reaction between the fibers and the metal or degradation of the fibers. Silicon nitride fibers are thermodynamically superior for use in aluminum or titanium metal matrix composites, since silicon nitride fibers are more stable at the temperatures required for full compaction. Secondary phase reactions are avoided.
Inventors
- 👤 K. Bhagwan Das
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:45
CPC Classifications
C; C22; C22C; C22C49/00; C22C49/02; C22C49/04; C22C47/00; C22C47/14; C22C49/10; C22C49/11; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12035; Y10T428/12049; Y10T428/12056
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
70 words
A method of producing a metal matrix composite, comprising the steps of: plastically deforming particles of the metal to impart strain energy thereto; mixing the strained metal particles with ceramic fibers to form a substantially uniform dispersion of fibers in the metal; and compacting the mixture at elevated temperatures to form a metal matrix composite of substantially full density without degrading the fibers or reacting the fibers with the metal.
Claim 2
Independent Claim
70 words
A method of producing a metal matrix composite, comprising the steps of: plastically deforming particles of the metal to impart strain energy thereto; mixing the strained metal particles with ceramic fibers to form a substantially uniform dispersion of fibers in the metal; and compacting the mixture at elevated temperatures to form a metal matrix composite of substantially full density without degrading the fibers or reacting the fibers with the metal.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the step of deforming reduces the diameter of the particles approximately about 60 to 80%.
Claim 4
Dependent Claim
11 words
The method of claim 2 wherein deforming the particles includes milling.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein the metal is a titanium alloy.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein compacting occurs at a temperature of about 500° to 700° C.
Claim 7
Dependent Claim
16 words
The method of claim 1 wherein the composite contains about 10 to 20 volume percent fibers.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein the fibers are silicon nitride whiskers.
Claim 9
Dependent Claim
10 words
The method of claim 1 wherein the metal includes aluminum.
Claim 10
Dependent Claim
17 words
The method of claim 8 including compacting occurs at a temperature of about 500° to 600° C.
Claim 11
Dependent Claim
11 words
The method of claim 4 wherein the fibers are silicon nitride.
Claim 12
Dependent Claim
39 words
The method of claim 1 wherein compacting occurs in two steps, namely compacting the mixture at room temperature to an intermediate density to form a green structure and then compacting the green structure to full density at elevated temperatures.
Claim 13
Independent Claim
106 words
A method of producing a metal matrix composite, comprising the steps of: plastically deforming metal matrix particles to impart strain energy to the particles; mixing the particles with reinforcing fibers to form a mixture; blending the mixture to form a substantially uniform dispersion of fibers in the particles; and compacting the mixture at elevated temperatures to form a composite having substantially full density, wherein the strain energy reduces the temperature required to obtain the desired density of and microstructure in the composite, the compacting occurring under such conditions that the fibers do not degrade substantially and substantially no interfacial reaction between the fibers and metal occurs.
Claim 14
Independent Claim
106 words
A method of producing a metal matrix composite, comprising the steps of: plastically deforming metal matrix particles to impart strain energy to the particles; mixing the particles with reinforcing fibers to form a mixture; blending the mixture to form a substantially uniform dispersion of fibers in the particles; and compacting the mixture at elevated temperatures to form a composite having substantially full density, wherein the strain energy reduces the temperature required to obtain the desired density of and microstructure in the composite, the compacting occurring under such conditions that the fibers do not degrade substantially and substantially no interfacial reaction between the fibers and metal occurs.
Claim 15
Dependent Claim
11 words
The method of claim 12 wherein blending includes vibrating the mixture.
Claim 16
Dependent Claim
15 words
The method of claim 12 wherein the particles are plastically deformed by milling the mixture.
Claim 17
Dependent Claim
12 words
The method of claim 12 wherein the particles are a titanium alloy.
Claim 18
Dependent Claim
12 words
The method of claim 12 wherein the particles are an aluminum alloy.
Claim 19
Dependent Claim
15 words
The method of claim 15 wherein compacting occurs at a temperature less than 700° C.
Claim 20
Dependent Claim
11 words
The method of claim 15 wherein the fibers are silicon nitride.
Claim 21
Dependent Claim
18 words
The method of claim 12 wherein the composite contains about 10 to 20 volume % silicon nitride fibers.
Claim 22
Dependent Claim
17 words
The method of claim 19 wherein the fibers have an aspect ratio of about 20 to 200.
Claim 23
Dependent Claim
9 words
An article made by the process of claim 1.
Claim 24
Dependent Claim
9 words
An article made by the process of claim 12.
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) | 1992-01-10 | 1992-07-11 | 1993-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-10 | 1996-07-11 | 1997-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-10 | 2000-07-11 | 2001-01-10 | $7700.00 | Window Closed / Lapsed |