US5221324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lightweight metal with isolated pores and its production
Assignee: Rio Tinto Alcan International Ltd
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Filing: 1992-06-29
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Granted: 1993-06-22
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Expires: 2012-06-29
Abstract
Abstract A novel lightweight gas metal composite is produced having isolated particle stabilized pores. A composite of a metal matrix, e.g. aluminum, and finely divided solid stabilizer particles, e.g. silicon carbide, is heated above the liquidus temperature of the metal matrix and this is mixed such that a vortex is formed. The molten composite is blanketed with a gas and during the vortex mixing. This gas is drawn into the melt to produce an expanded, viscous molten composite material containing pores which are very small, spherical-shaped and quite evenly distributed. The viscous molten composite material can be directly formed into a solid shaped product and is also capable of being remelted and formed by forming processes without destroying the integrity of the pores. The result is a lightweight expanded metal product capable of being formed into shapes to close dimensional tolerances.
Inventors
- 👤 Iljoon Jin
- 👤 Lorne D. Kenny
- 👤 Harry Sang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:02
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/08; B; B22; B22D; B22D25/00; B22D25/005; C22C1/083; C22C1/086; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/1234
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
108 words
A process for producing a lightweight gas-metal composite containing isolated particle-stabilized pores, comprising the steps of: heating a composite of a metal matrix and finely divided solid stabilizer particles above the liquidus temperature of the metal matrix to form a molten metal composite; mixing the molten metal composite whereby a vortex is formed and continuing the mixing while drawing a gas into the molten composite by way of the vortex until an expanded, viscous molten composite material is formed; and cooling the expanded material below the solidus temperature of the melt to form a lightweight solid metal product having distributed therethrough a plurality of small isolated, particle-stabilized pores.
Claim 2
Dependent Claim
108 words
A process for producing a lightweight gas-metal composite containing isolated particle-stabilized pores, comprising the steps of: heating a composite of a metal matrix and finely divided solid stabilizer particles above the liquidus temperature of the metal matrix to form a molten metal composite; mixing the molten metal composite whereby a vortex is formed and continuing the mixing while drawing a gas into the molten composite by way of the vortex until an expanded, viscous molten composite material is formed; and cooling the expanded material below the solidus temperature of the melt to form a lightweight solid metal product having distributed therethrough a plurality of small isolated, particle-stabilized pores.
Claim 3
Dependent Claim
26 words
A process according to claim 1, wherein the stabilizer particles are present in the metal matrix composite in an amount of less than 25% by volume.
Claim 4
Dependent Claim
21 words
A process according to claim 2, wherein the stabilizer particles have sizes in the range of about 0.1 to 50 μm.
Claim 5
Dependent Claim
36 words
A process according to claim 3, wherein the stabilizer particles have sizes in the range of about 0.5 to 25 μm and are present in the composite in an amount of 5 to 15% by volume.
Claim 6
Dependent Claim
15 words
A process according to claim 3, wherein the stabilizer particles are ceramic or intermetallic particles.
Claim 7
Dependent Claim
17 words
A process according to claim 3, wherein the stabilizer particles are metal oxides, carbides, nitrides or borides.
Claim 8
Dependent Claim
26 words
A process according to claim 3, wherein the stabilizer particles are selected from the group consisting of alumina, titanium diboride, zirconia, silicon carbide and silicon nitride.
Claim 9
Dependent Claim
23 words
A process according to claim 3, wherein the mixing is continued until the expanded molten metal composite has a pasty or viscous consistency.
Claim 10
Dependent Claim
21 words
A process according to claim 1, wherein the expanded, viscous molten composite material is formed into a shaped, lightweight metal product.
Claim 11
Dependent Claim
21 words
A process according to claim 1, wherein the solid metal product is remelted and formed into a shaped, lightweight metal product.
Claim 12
Dependent Claim
16 words
A process according to claims 9 or 10, wherein the forming comprises die-casting or thixotropic shaping.
Claim 13
Dependent Claim
14 words
A process according to claim 11 wherein the thixotropic shaping is thixo-extrusion or thixo-forging.
Claim 14
Dependent Claim
16 words
A process according to claim 1, wherein the metal matrix is aluminum or an alloy thereof.
Claim 15
Dependent Claim
52 words
A stabilized, lightweight metal body, comprising: a metal matrix having finely divided solid stabilizer particles dispersed therethrough; and said body also having dispersed therethrough a plurality of closed and isolated pores, with the stabilizer particles contained in the matrix being concentrated adjacent the interfaces between the matrix metal and the closed pores.
Claim 16
Dependent Claim
52 words
A stabilized, lightweight metal body, comprising: a metal matrix having finely divided solid stabilizer particles dispersed therethrough; and said body also having dispersed therethrough a plurality of closed and isolated pores, with the stabilizer particles contained in the matrix being concentrated adjacent the interfaces between the matrix metal and the closed pores.
Claim 17
Dependent Claim
21 words
A metal body according to claim 14, wherein the pores are spherical and have sizes in the range of 10-500 microns.
Claim 18
Dependent Claim
25 words
A metal body according to claim 15, wherein the pores are spaced from each other by an average distance of about 50 to 100 microns.
Claim 19
Dependent Claim
26 words
A metal body according to claim 16, wherein the metal body is a shaped body having smooth outer faces and a core with said spaced pores.
Claim 20
Dependent Claim
27 words
A metal body according to claim 16, wherein the stabilizer particles are present in the metal matrix composite in an amount of less than 25% by volume.
Claim 21
Dependent Claim
22 words
A metal body according to claim 18, wherein the stabilizer particles have sizes in the range of about 0.1 to 50 microns.
Claim 22
Dependent Claim
16 words
A metal body according to claim 19, wherein the stabilizer particles are ceramic or intermetallic particles.
Claim 23
Dependent Claim
17 words
A metal body according to claim 20, wherein the metal matrix is aluminium or an alloy thereof.
Claim 24
Dependent Claim
18 words
A metal body according to claim 21, wherein the stabilizer particles are metal oxides, carbides, nitrides or borides.
Claim 25
Dependent Claim
18 words
A metal body according to claim 14, having a relative density of from about 0.3 to about 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-06-21 | 1996-12-21 | 1997-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-21 | 2000-12-21 | 2001-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-21 | 2004-12-21 | 2005-06-22 | $7700.00 | Window Closed / Lapsed |