US5028392A
Expired / Lapsed
US
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Melt process for the production of metal-matrix composite materials with enhanced particle/matrix wetting
Assignee: Rio Tinto Alcan International Ltd
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Filing: 1990-06-14
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Granted: 1991-07-02
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Expires: 2010-06-14
Abstract
Abstract A metal matrix composite material containing discontinuous particles in a metallic matrix is prepared by forming a mixture of the molten alloy and the particles in a closed reactor, removing oxygen from the interior of the reactor, statically pressurizing the interior of the reactor with nitrogen gas, mixing the mixture of the molten alloy and particles in the presence of the static nitrogen gas to wet the molten matrix to the particles, and evacuating the interior of the reactor in a stepwise manner. The nitrogen gas aids in wetting the metallic alloy to the particles by forming aluminum nitride at the particle-molten matrix interface, so that a lower contact angle of the alloy to the particle results. Oxygen that may be present in the sealed reactor is gettered by the aluminum, and the nitrogen is removed by stepwise evacuation, thereby minimizing the introduction of gas into, and retention of gas within, the melt.
Inventors
- 👤 David J. Lloyd
- 👤 Alan D. McLeod
- 👤 Philip L. Morris
- 👤 Iljoon Jin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:11
CPC Classifications
B; B22; B22D; B22D1/00; C; C22; C22C; C22C1/00; C22C1/10; C22C1/1036; C22C32/00; C22C32/001; C22C32/0015; C22C32/0036; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12486
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
105 words
A process for preparing a metal matrix composite material, comprising the steps of: preparing in a closed reactor a mixture of a molten aluminum alloy containing at least some magnesium, and particles that do not dissolve in the aluminum alloy, the particles being present in an amount of less than about 35 volume percent of the total mixture; applying a vacuum to the mixture; statically pressurizing the interior of the reactor with nitrogen gas; mixing the mixture of aluminum alloy and particles under the static nitrogen atmosphere to wet the particles with the alloy; and evacuating the interior of the reactor in a stepwise manner.
Claim 2
Dependent Claim
105 words
A process for preparing a metal matrix composite material, comprising the steps of: preparing in a closed reactor a mixture of a molten aluminum alloy containing at least some magnesium, and particles that do not dissolve in the aluminum alloy, the particles being present in an amount of less than about 35 volume percent of the total mixture; applying a vacuum to the mixture; statically pressurizing the interior of the reactor with nitrogen gas; mixing the mixture of aluminum alloy and particles under the static nitrogen atmosphere to wet the particles with the alloy; and evacuating the interior of the reactor in a stepwise manner.
Claim 3
Dependent Claim
20 words
The process of claim 1, wherein the molten aluminum alloy has less than about 1 percent by weight of magnesium.
Claim 4
Dependent Claim
17 words
The process of claim 1, wherein the molten aluminum alloy has about 0.15 percent by weight magnesium.
Claim 5
Dependent Claim
13 words
The process of claim 1, wherein the molten aluminum alloy further contains copper.
Claim 6
Dependent Claim
13 words
The process of claim 1, wherein the molten aluminum alloy further contains silicon.
Claim 7
Dependent Claim
11 words
The process of claim 1, wherein the particles are aluminum oxide.
Claim 8
Dependent Claim
23 words
The process of claim 1, wherein the pressure of the nitrogen gas in the step of statically pressurizing is greater than one atmosphere.
Claim 9
Dependent Claim
84 words
The process of claim 1, wherein the step of evacuating the mixture includes the steps of: evacuating the mixture to about 600 torr for at least about 2 minutes; evacuating the mixture to about 400 torr for at least about 2 minutes; evacuating the mixture to about 200 torr for at least about 2 minutes; evacuating the mixture to about 100 torr for at least about 2 minutes; and evacuating the mixture to less than about 1 torr for at least about 10 minutes.
Claim 10
Dependent Claim
18 words
The process of claim 1, including the additional step, after the step of evacuating, of solidifying the mixture.
Claim 11
Dependent Claim
103 words
A process for preparing a metal matrix composite material, comprising the steps of: preparing in a closed reactor a mixture of a molten aluminum alloy containing at least some magnesium, and particles that do not dissolve in the molten aluminum alloy, the particles being present in an amount of less than about 35 volume percent of the total mixture; applying a vacuum to the mixture; statically pressurizing the interior of the reactor with nitrogen gas; mixing the mixture of aluminum alloy and particles under the static nitrogen atmosphere to wet the particles with the alloy; and removing the nitrogen gas from the mixture.
Claim 12
Dependent Claim
103 words
A process for preparing a metal matrix composite material, comprising the steps of: preparing in a closed reactor a mixture of a molten aluminum alloy containing at least some magnesium, and particles that do not dissolve in the molten aluminum alloy, the particles being present in an amount of less than about 35 volume percent of the total mixture; applying a vacuum to the mixture; statically pressurizing the interior of the reactor with nitrogen gas; mixing the mixture of aluminum alloy and particles under the static nitrogen atmosphere to wet the particles with the alloy; and removing the nitrogen gas from the mixture.
Claim 13
Dependent Claim
82 words
A process for preparing a metal matrix composite material, comprising the steps of: preparing in a closed reactor a mixture of a molten aluminum alloy, and particles that do not dissolve in the aluminum alloy; and wetting the molten aluminum alloy to the particles under conditions such that the partial pressure of oxygen gas is below the pressure required for the formation of aluminum oxide and the partial pressure of nitrogen gas is above that required for the formation of aluminum nitride.
Claim 14
Dependent Claim
82 words
A process for preparing a metal matrix composite material, comprising the steps of: preparing in a closed reactor a mixture of a molten aluminum alloy, and particles that do not dissolve in the aluminum alloy; and wetting the molten aluminum alloy to the particles under conditions such that the partial pressure of oxygen gas is below the pressure required for the formation of aluminum oxide and the partial pressure of nitrogen gas is above that required for the formation of aluminum nitride.
Claim 15
Dependent Claim
19 words
The process of claim 11, wherein the step of wetting is accomplished by mixing the mixture with an impeller.
Claim 16
Dependent Claim
26 words
The process of claim 11, wherein the step of wetting is accomplished in a closed vessel with a static pressurization of nitrogen over the molten mixture.
Claim 17
Dependent Claim
45 words
The process of claim 11, wherein the step of wetting includes the steps of: mixing the molten metal with an impeller in a closed vessel under a static pressurization of nitrogen, and evacuating the nitrogen from the interior of the vessel in a stepwise manner.
Claim 18
Dependent Claim
23 words
The process of claim 11, wherein the molten aluminum alloy contains from about 0.03 weight percent to about 1 weight percent of magnesium.
Claim 19
Dependent Claim
17 words
The process of claim 11, wherein the molten aluminum alloy has about 0.15 percent by weight magnesium.
Claim 20
Dependent Claim
13 words
The process of claim 11, wherein the molten aluminum alloy further contains copper.
Claim 21
Dependent Claim
13 words
The process of claim 11, wherein the molten aluminum alloy further contains silicon.
Claim 22
Dependent Claim
11 words
The process of claim 11, wherein the particles are aluminum oxide.
Claim 23
Dependent Claim
23 words
The process of claim 11, wherein the partial pressure of the nitrogen gas in the step of wetting is greater than one atmosphere.
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) | 1994-07-01 | 1994-12-31 | 1995-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-01 | 1998-12-31 | 1999-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-01 | 2002-12-31 | 2003-07-02 | $7700.00 | Window Closed / Lapsed |