US4573516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for casting directionally solidified articles
Assignee: UK Secretary of State for Defence
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Filing: 1983-11-02
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Granted: 1986-03-04
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Expires: 2003-11-02
Abstract
Abstract A ceramic mould is supported on a stainless steel platform carried at the upper end of a water-cooled tube surrounded by a copper cylinder containing alumina powder of approximately 100 μm particle size which is fluidized by an inert gas. Metal in the mould is melted by a furnace which surrounds the mould and the mould is progressively withdrawn into the fluidized bed by which heat is extracted and transferred to water cooled coils surrounding the copper cylinder. In a modification, the inert gas is drawn from the fluidized bed by way of a filter and vacuum pump whereby the outlet pressure is reduced to about 1 torr. This reduces the risk of contamination of the alloy and permits re-use of expensive cooling gases.
Inventors
- 👤 Peter N. Quested
- 👤 James E. Northwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:21
CPC Classifications
C; C30; C30B; C30B11/00; C30B29/00; C30B29/10; C30B29/52
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
92 words
A method of controlling the formation of a crystalline structure comprising the steps of: (a) progressively melting a crystalline material by effecting relative axial movement of the crystalline material with respect to a heat source; and (b) subsequently extracting heat from the molten material to directionally solidify the molten material in step with the melting of step (a) to form an aligned crystalline microstructure wherein the extraction of heat from the molten material is accomplished by means of a fluidized bed of a fine chemically inert powder fluidized by an inert gas.
Claim 2
Independent Claim
92 words
A method of controlling the formation of a crystalline structure comprising the steps of: (a) progressively melting a crystalline material by effecting relative axial movement of the crystalline material with respect to a heat source; and (b) subsequently extracting heat from the molten material to directionally solidify the molten material in step with the melting of step (a) to form an aligned crystalline microstructure wherein the extraction of heat from the molten material is accomplished by means of a fluidized bed of a fine chemically inert powder fluidized by an inert gas.
Claim 3
Dependent Claim
30 words
A method of controlling the formation of a crystalline structure according to claim 1 in which the molten material is removed progressively from the heat source into the fluidized bed.
Claim 4
Independent Claim
99 words
A method of producing an aligned crystalline microstructure, said method comprising the steps of: (a) progressively melting a crystalline material by effecting relative axial movement between the crystalline material and a heat source; and (b) controlling the directional solidification of the molten material produced according to step (a) by extracting heat therefrom by moving the molten material through a fluidized bed of a fine chemically inert powder fluidized by an inert gas to suppress nucleation of the molten material ahead of the advancing interface between the molten material and the directional solidified material to produce an aligned crystalline microstructure.
Claim 5
Independent Claim
99 words
A method of producing an aligned crystalline microstructure, said method comprising the steps of: (a) progressively melting a crystalline material by effecting relative axial movement between the crystalline material and a heat source; and (b) controlling the directional solidification of the molten material produced according to step (a) by extracting heat therefrom by moving the molten material through a fluidized bed of a fine chemically inert powder fluidized by an inert gas to suppress nucleation of the molten material ahead of the advancing interface between the molten material and the directional solidified material to produce an aligned crystalline microstructure.
Claim 6
Dependent Claim
27 words
A method of controlling the formation of a crystalline structure according to claim 1, claim 2 or claim 3 in which the powder is a stable ceramic.
Claim 7
Dependent Claim
34 words
A method of controlling the formation of a crystalline structure according to claim 1, claim 2 or claim 3 in which the particle size of the powder is of the order of 100 μm.
Claim 8
Dependent Claim
28 words
A method of controlling the formation of a crystalline structure according to claim 1, claim 2 or claim 3 in which the crystalline material is a metal alloy.
Claim 9
Dependent Claim
27 words
A method of controlling the formation of a crystalline structure according to claim 1, claim 2 or claim 3 wherein the crystalline material is a nickel-base alloy.
Claim 10
Dependent Claim
32 words
A method of controlling the formation of a crystalline structure according to claim 1, claim 2 or claim 3 in which the gas is drawn from the fluidized bed at sub-atmospheric pressure.
Claim 11
Dependent Claim
24 words
A method of controlling the formation of a crystalline structure according to claim 8 in which the gas outlet pressure is substantially 133 Pa.
Claim 12
Independent Claim
58 words
A method of casting a metal article having aligned crystalline microstructures, said method comprising the steps of introducing a nickel-base alloy into a mould, progressively melting the alloy by effecting relative movement between the mould and a heat source, and directionally solidifying the molten alloy by transferring heat therefrom to a fluidized bed to produce aligned crystalline microstructures.
Claim 13
Independent Claim
58 words
A method of casting a metal article having aligned crystalline microstructures, said method comprising the steps of introducing a nickel-base alloy into a mould, progressively melting the alloy by effecting relative movement between the mould and a heat source, and directionally solidifying the molten alloy by transferring heat therefrom to a fluidized bed to produce aligned crystalline microstructures.
Claim 14
Dependent Claim
26 words
A method of casting a metal article according to claim 10 in which the mould is removed progressively from the heat source into the fluidized bed.
Claim 15
Dependent Claim
27 words
A method of casting a metal article according to claim 10 or claim 11 in which solidification of the molten alloy is initiated by a water-cooled chill.
Claim 16
Dependent Claim
30 words
A method of casting a metal article according to claim 10 or claim 11 in which the fluidized bed comprises a fine chemically inert powder fluidized by an inert gas.
Claim 17
Dependent Claim
19 words
A method of casting a metal article according to claim 13 in which the powder is a stable ceramic.
Claim 18
Dependent Claim
17 words
A method of casting a metal article according to claim 13 in which the powder is alumina.
Claim 19
Dependent Claim
17 words
A method of casting a metal article according to claim 13 in which the gas is helium.
Claim 20
Dependent Claim
24 words
A method of casting a metal article according to claim 13 in which the gas is drawn from the fluidized bed at subatmospheric pressure.
Claim 21
Dependent Claim
21 words
A method of casting a metal article according to claim 17 in which the gas outlet pressure is substantially 133 Pa.
Claim 22
Dependent Claim
83 words
Apparatus for metal casting comprising: an open-ended mould, a hollow metal platform through which water can be circulated for carrying said mould, a heating chamber to heat the mould, a fluidizable bed for cooling the mould, and means for first moving the platform, and thus said mould, axially through said heating chamber and then on through said fluidizable bed to thereby progressively heat a portion of said mould in said heating chamber prior to cooling of the mould portion in said fluidizable bed.
Claim 23
Dependent Claim
83 words
Apparatus for metal casting comprising: an open-ended mould, a hollow metal platform through which water can be circulated for carrying said mould, a heating chamber to heat the mould, a fluidizable bed for cooling the mould, and means for first moving the platform, and thus said mould, axially through said heating chamber and then on through said fluidizable bed to thereby progressively heat a portion of said mould in said heating chamber prior to cooling of the mould portion in said fluidizable bed.
Claim 24
Dependent Claim
33 words
Apparatus for metal casting according to claim 19 in which the fluidizable bed comprises a fine chemically inert powder material and gas-introducing means for introducing an inert fluidizing gas into said powder material.
Claim 25
Dependent Claim
16 words
Apparatus for metal casting according to claim 20 in which the powder material is a ceramic.
Claim 26
Dependent Claim
15 words
Apparatus for metal casting according to claim 21 in which the powder material is alumina.
Claim 27
Dependent Claim
23 words
Apparatus for metal casting according to claim 19, claim 20 or claim 21 wherein said gas introducing means is adapted to introduce helium.
Claim 28
Dependent Claim
29 words
Apparatus for metal casting according to claim 19, claim 20 or claim 21 further comprising vacuum means for withdrawing the gas from the fluidizable bed at a sub-atmospheric pressure.
Claim 29
Dependent Claim
28 words
Apparatus for metal casting according to claim 23 wherein said vacuum means is adapted to withdraw gas from said fluidizable bed at a pressure of substantially 133 Pa.
Claim 30
Independent Claim
196 words
An apparatus for metal casting comprising: an open ended mould for accepting an quantity of crystalline material therein; means defining a heating zone including heat source means for melting the crystalline material in said mould to form a molten material; means defining a cooling zone downstream of said heating zone, said cooling zone including a bed of fine chemically inert powder and fluidizing means in fluid communication with said bed for introducing an inert gas therein to fluidize said bed; and means connected to said mould for first moving said mould through said heating zone to progressively melt said crystalline material therein and then for moving said mould through said cooling zone to effect heat transfer between the molten material and the fluidized bed to progressively directionally solidify the molten material and for controlling the recrystallization of the molten material to produce an aligned crystalline microstructure by suppressing the nucleation of the molten material ahead of the interface between the molten material and the directionally solidified material as said interface advances in relative position in said mould by virtue of said mould being progressively moved first through said heating zone and then through said cooling zone.
Claim 31
Independent Claim
196 words
An apparatus for metal casting comprising: an open ended mould for accepting an quantity of crystalline material therein; means defining a heating zone including heat source means for melting the crystalline material in said mould to form a molten material; means defining a cooling zone downstream of said heating zone, said cooling zone including a bed of fine chemically inert powder and fluidizing means in fluid communication with said bed for introducing an inert gas therein to fluidize said bed; and means connected to said mould for first moving said mould through said heating zone to progressively melt said crystalline material therein and then for moving said mould through said cooling zone to effect heat transfer between the molten material and the fluidized bed to progressively directionally solidify the molten material and for controlling the recrystallization of the molten material to produce an aligned crystalline microstructure by suppressing the nucleation of the molten material ahead of the interface between the molten material and the directionally solidified material as said interface advances in relative position in said mould by virtue of said mould being progressively moved first through said heating zone and then through said cooling zone.
Claim 32
Independent Claim
69 words
A method of producing a metallic component having aligned crystalline grain structure comprising the steps of: (a) providing a mould containing molten metal to be solidified; (b) effecting relative axial movement of the mould containing the molten metal to be solidified from a heating zone to a cooling zone; wherein said cooling zone consists of a fluidized bed of a fine chemically inert powder fluidized by an inert gas.
Claim 33
Independent Claim
69 words
A method of producing a metallic component having aligned crystalline grain structure comprising the steps of: (a) providing a mould containing molten metal to be solidified; (b) effecting relative axial movement of the mould containing the molten metal to be solidified from a heating zone to a cooling zone; wherein said cooling zone consists of a fluidized bed of a fine chemically inert powder fluidized by an inert gas.
Claim 34
Dependent Claim
98 words
Apparatus for metal casting comprising: a mould for containing a quantity of metal; a heating chamber establishing a heating zone for heating the mould; a cooling chamber, downstream of said heating chamber, establishing a cooling zone for cooling said mould downstream of said heating zone, said cooling chamber including a bed of a fluidizable material and means in fluid communication with said bed for fluidizing said fluidizable material; and drive means connected to said mould for effecting progressive axial movement of said mould between said heating and cooling zones to thereby progressively heat and cool said mould, respectively.
Claim 35
Dependent Claim
98 words
Apparatus for metal casting comprising: a mould for containing a quantity of metal; a heating chamber establishing a heating zone for heating the mould; a cooling chamber, downstream of said heating chamber, establishing a cooling zone for cooling said mould downstream of said heating zone, said cooling chamber including a bed of a fluidizable material and means in fluid communication with said bed for fluidizing said fluidizable material; and drive means connected to said mould for effecting progressive axial movement of said mould between said heating and cooling zones to thereby progressively heat and cool said mould, respectively.
Claim 36
Dependent Claim
23 words
Apparatus as in claim 28 wherein said cooling chamber includes walls and cooling means for circulating a cooling fluid to cool said walls.
Claim 37
Dependent Claim
18 words
Apparatus as in claim 28 further comprising platform means connected to said drive means for carrying said mould.
Claim 38
Dependent Claim
22 words
Apparatus as in claim 30 wherein said platform means includes means for providing a path through which a cooling fluid can pass.
Claim 39
Dependent Claim
11 words
Apparatus as in claim 31 wherein said platform means is hollow.
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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) | 1989-03-03 | 1989-09-02 | 1990-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-03 | 1993-09-02 | 1994-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-03 | 1997-09-02 | 1998-03-04 | $7700.00 | Window Closed / Lapsed |