US5989476A
Expired / Lapsed
US
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Process of making a molded refractory article
Assignee: 3D Systems Inc
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Filing: 1998-06-12
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Granted: 1999-11-23
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Expires: 2018-06-12
Abstract
Abstract A method for making a molded refractory article including the steps of providing a mold including a master pattern, the mold and master pattern defining a mold cavity; filling the mold cavity with a mixture comprising refractory particles and a heat fugitive binder; placing the assembly of the mold, master pattern and mixture in a furnace; curing the mixture; separating the mold and master pattern from the cured mixture; removing the binder to form a porous structure, sintering the porous structure to provide a porous refractory article and infiltrating the porous refractory article with a filler metal.
Inventors
- 👤 Michael S. Lockard
- 👤 Kris Schmidt
- 👤 Charles W. Hull
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:50
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/10; C22C1/1005; C22C1/1015; B; B22; B22F; B22F3/00; B22F3/10; B22F3/1017; B22F3/1021; B22F3/12; B22F3/1208; B22F3/1258; B22F3/1283; B22F3/1291; B22F2998/00; B22F2998/10; B22F2999/00; B33; B33Y; B33Y80/00; Y; Y02; Y02P; Y02P10/00; Y02P10/25
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
180 words
A method for making a molded refractory article comprising the steps of: a) providing a mold including a master pattern, the mold and master pattern defining a molding pattern, at least the master pattern being formed using a stereolithographic or selective deposition modeling process; b) filling the molding pattern in proximity to the master pattern with a mixture comprising refractory particles and a heat fugitive binder; c) curing the mixture; d) heating the mold and cured mixture to a predetermined temperature for a predetermined time so as to cause the master pattern to melt, oxidize, or reduce, leaving a molded refractory particle/binder article with a mold pattern thereon substantially duplicating the master pattern; e) heating the molded refractory particle/binder article to a temperature sufficient to cause the binder to leave the molded refractory particle/binder article to form a porous refractory article, and f) heating the porous refractory article to a temperature greater than in step e) to cause the refractory particles to adhere to each other forming a sintered porous refractory article; the resultant product being a porous refractory article.
Claim 2
Independent Claim
180 words
A method for making a molded refractory article comprising the steps of: a) providing a mold including a master pattern, the mold and master pattern defining a molding pattern, at least the master pattern being formed using a stereolithographic or selective deposition modeling process; b) filling the molding pattern in proximity to the master pattern with a mixture comprising refractory particles and a heat fugitive binder; c) curing the mixture; d) heating the mold and cured mixture to a predetermined temperature for a predetermined time so as to cause the master pattern to melt, oxidize, or reduce, leaving a molded refractory particle/binder article with a mold pattern thereon substantially duplicating the master pattern; e) heating the molded refractory particle/binder article to a temperature sufficient to cause the binder to leave the molded refractory particle/binder article to form a porous refractory article, and f) heating the porous refractory article to a temperature greater than in step e) to cause the refractory particles to adhere to each other forming a sintered porous refractory article; the resultant product being a porous refractory article.
Claim 3
Dependent Claim
45 words
The method of claim 1, also including the step of infiltrating the sintered porous article with a metallic filler wherein the infiltrating step utilizes a relatively low melting point molten metal infiltrant to fill the pores, the resultant product being an article having a cavity.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein step a) and b) are performed simultaneously.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein the heat applied in step e) is greater than in step d).
Claim 6
Dependent Claim
29 words
The method of claim 1 wherein all of the steps are performed in a single oven programmed with temperatures and time periods sufficient to perform each step in series.
Claim 7
Dependent Claim
14 words
The method of claim 1 further including mechanical removal of portions of the mold.
Claim 8
Independent Claim
163 words
A method for making a molded refractory article comprising the steps of: providing a mold having a cavity therein corresponding to a master pattern substantially duplicating an article to be formed, the mold being formed using a stereolithographic or selective deposition modeling process; filling the mold cavity with a mixture comprising refractory particles in a liquid heat-fugitive binder; placing the mold and mixture in a furnace and raising the temperature within the furnace over a predetermined temperature and time schedule so as to cause, in order, a) the heat fugitive binder to cure to a solid, b) the mold to melt, oxidize, or reduce, leaving a molded refractory particle/binder article, c) the binder to leave the molded refractory particle/binder article to form a substantially binder free porous refractory article, and d) the refractory particles in the substantially binder free porous refractory article to adhere to provide a sintered porous molded refractory article; wherein said sintered porous molded refractory article duplicates the master pattern.
Claim 9
Independent Claim
163 words
A method for making a molded refractory article comprising the steps of: providing a mold having a cavity therein corresponding to a master pattern substantially duplicating an article to be formed, the mold being formed using a stereolithographic or selective deposition modeling process; filling the mold cavity with a mixture comprising refractory particles in a liquid heat-fugitive binder; placing the mold and mixture in a furnace and raising the temperature within the furnace over a predetermined temperature and time schedule so as to cause, in order, a) the heat fugitive binder to cure to a solid, b) the mold to melt, oxidize, or reduce, leaving a molded refractory particle/binder article, c) the binder to leave the molded refractory particle/binder article to form a substantially binder free porous refractory article, and d) the refractory particles in the substantially binder free porous refractory article to adhere to provide a sintered porous molded refractory article; wherein said sintered porous molded refractory article duplicates the master pattern.
Claim 10
Dependent Claim
31 words
The method of claim 7 which includes the additional step of infiltrating the sintered porous molded refractory article with a relatively low melting point molten metal infiltrant to fill the pores.
Claim 11
Independent Claim
108 words
A method for making an article comprising the steps of: providing a mold; disposing a master pattern within the mold to define a mold cavity; filling the mold cavity around the master pattern with a mixture comprising refractory particles and a heat fugitive binder to form a cast assembly; placing the cast assembly in a furnace, the furnace programmed to heat to preset temperatures over a fixed period of time, the preset temperatures held constant for a predetermined period of time; curing the mixture; separating the mold and master pattern from the cured mixture; removing the binder from the cured mixture; and sintering the binder free cured mixture.
Claim 12
Independent Claim
108 words
A method for making an article comprising the steps of: providing a mold; disposing a master pattern within the mold to define a mold cavity; filling the mold cavity around the master pattern with a mixture comprising refractory particles and a heat fugitive binder to form a cast assembly; placing the cast assembly in a furnace, the furnace programmed to heat to preset temperatures over a fixed period of time, the preset temperatures held constant for a predetermined period of time; curing the mixture; separating the mold and master pattern from the cured mixture; removing the binder from the cured mixture; and sintering the binder free cured mixture.
Claim 13
Dependent Claim
23 words
The method of claim 6 further including the step of infiltrating a molten metal into open spaces within the porous molded refractory article.
Claim 14
Dependent Claim
25 words
The method of claim 1 wherein the mixture is cured at about 30° to 40° C. for from about 16 hours to about 24 hours.
Claim 15
Dependent Claim
40 words
The method of claim 1 wherein the mold and cured mixture is heated to between about 50° C. to about 140° C. for about 30 minutes to about 60 minutes to remove the master pattern to leave a cured mold.
Claim 16
Dependent Claim
35 words
The method of claim 12 wherein the cured mold is heated to a temperature from about 850° C. to about 950° C. and held at that temperature for about 30 hours to about 45 hours.
Claim 17
Dependent Claim
55 words
The method of claim 1 wherein the porous sintered product is further heated to a temperature from about 900° C. to about 1150° C. for from about 20 minutes to about 250 minutes while the porous sintered product is in contact with a metal to cause the metal to infiltrate into the porous sintered product.
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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) | 2002-11-22 | 2003-05-24 | 2003-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-22 | 2007-05-24 | 2007-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-22 | 2011-05-24 | 2011-11-23 | $7700.00 | Window Closed / Lapsed |