With Particular Binder Patents (Class 164/518)
  • Patent number: 10350673
    Abstract: A method of manufacturing a hollow salt core may include an injection operation, in which molten salt including an ingredient of a salt core is injected into a mold through pressurization; a primary maintenance operation, in which a pressure is maintained in the mold including the injected molten salt; a primary decompressing operation, in which a portion of the molten salt maintained with the pressure is collected in the mold through decompression of the mold; a secondary maintenance operation, in which a pressure is maintained in the mold including the residual molten salt after the primary decompressing operation; and a secondary decompressing operation, in which the pressure of the mold is decreased after the secondary maintenance operation.
    Type: Grant
    Filed: June 14, 2017
    Date of Patent: July 16, 2019
    Assignees: Hyundai Motor Company, Kia Motors Corporation
    Inventors: Cheol-Ung Lee, Ji-Yong Lee
  • Patent number: 9314838
    Abstract: A method of manufacturing a cooled turbine blade for use in a gas turbine engine. The method includes forming an inner blade pattern, the inner blade pattern including an inner spar and a plurality of inner spar cooling fins. The method also includes forming an inner blade core, removing the inner blade pattern from the inner blade core, forming an outer blade pattern, forming a casting shell, removing the outer blade pattern from the casting shell, and casting the cooled turbine blade in the casting shell. The method also includes removing the casting shell from the cast cooled turbine blade, and removing the inner blade core from the cast cooled turbine blade.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: April 19, 2016
    Assignee: Solar Turbines Incorporated
    Inventors: Stephen Edward Pointon, Andrew Meier, Nnawuihe Asonye Okpara, Daniel Martinez
  • Patent number: 8770260
    Abstract: The process for investment casting of complex shapes has historically had 6 basic steps in it. Depending upon the path taken, these discrete steps have been reduced to either 5 steps, or to 2 steps, discarding the unwanted steps. Instead of having to generate the shape of each sacrificial pattern, the process generates either (A) a male tree containing a plurality of sacrificial patterns, already on their runners, onto which a mold shell can be formed, or, (B) a female shell, made of a refractory material, and forming internally the outside surfaces of the plurality of patterns and runners. This process removes both capital expenditure for tooling and process time by up to 90%. By removing several lengthy, time-dependant steps from the process the part cost and lead time are reduced.
    Type: Grant
    Filed: June 24, 2009
    Date of Patent: July 8, 2014
    Assignee: Borg Warner Inc.
    Inventor: Stephen I. Roby
  • Patent number: 8210240
    Abstract: A casting process and apparatus for producing directionally-solidified castings, and castings produced therewith. The process entails applying a facecoat slurry to a surface within a mold cavity to form a continuous solid facecoat on the surface, introducing a molten metal alloy into the mold cavity so that the molten metal alloy contacts the facecoat, and then immersing the mold in a liquid coolant to cool and solidify the molten metal alloy and form a casting of the metal alloy, during which an oxide layer forms on the casting surface. The facecoat is sufficiently adherent to the oxide layer such that at least a portion of the facecoat detaches from the mold surface and remains tightly adhered to the casting surface in the event the casting contracts during cooling. The facecoat contains at least 60 weight percent of a first phase of yttria, and the balance of the facecoat is a binder phase of an inorganic material.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: July 3, 2012
    Assignee: General Electric Company
    Inventors: Shyh-Chin Huang, Stephen Francis Rutkowski, Michael Francis Xavier Gigliotti, Jr., Roger John Petterson, Lawrence Bernard Kool
  • Patent number: 8122942
    Abstract: A slurry suitable for forming facecoats, facecoats formed by such a slurry, and processes using such facecoats. The slurry is formed of a particulate refractory material, an aqueous suspension containing a particulate inorganic binder, a thixotropic organic binder, a dispersant, and possibly optional constituents excluding particulate refractory materials and inorganic binders. The particulate refractory material constitutes at least about 60 weight percent of the slurry and consists essentially of yttria. The aqueous suspension containing the particulate inorganic binder constitutes at most about 35 weight percent of the facecoat slurry. The dispersant is present in the slurry in an amount sufficient to stabilize the slurry at a pH of up to about 10, and has the general formula Hx[N(CH2)yOH]z, where x has a value of 0, 1 or 2, y has a value of 1 to 8, and z=3?x.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: February 28, 2012
    Assignee: General Electric Company
    Inventors: Stephen Francis Rutkowski, Lawrence Bernard Kool
  • Patent number: 8042599
    Abstract: The invention relates to a method and to a device for sing out this method, during which the shell molds (3) are filled with a melt (11) in a clocked manner, the respectively required amount of melt being currently provided at the same time. The casting process ensues by marrying the crucible (6), which is filled with a melt (11), with a shell mold (3) so that the crucible (6) and shell mold (3) form a common cavity (10), and this arrangement is subsequently tilted 180°, so that the melt (11) falls into the shell mold (3).
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: October 25, 2011
    Assignee: ALD Vacuum Technologies GmbH
    Inventor: Pavel Seserko
  • Patent number: 7258158
    Abstract: Method and apparatus for prolonging the stability (working life) of a ceramic slurry and other aqueous mixture or dispersion containing a liquid silica-bearing or other component as well as the raw liquid silica-bearing component in ambient air over time by providing a gas blanket that reduces exposure to ambient air.
    Type: Grant
    Filed: July 21, 2005
    Date of Patent: August 21, 2007
    Assignee: Howmet Corporation
    Inventors: Bart M. Kilinski, Eliot S. Lassow, William B. Carothers
  • Patent number: 7128129
    Abstract: A composition and method for forming investment casting shells includes using colloidal silica, zircon flour, and fused silica in a slurry which is applied to a pattern. After the slurry is applied to the pattern, it is allowed to partially or completely solidify. After the shell has solidified, the pattern may be melted or otherwise removed. A molten material is introduced into the shell and allowed to cool to form an article. Finally, the shell is broken away or otherwise removed from the article. The improved shell slurry composition and corresponding method minimizes pattern-to-pour cycle times and is environmentally friendly.
    Type: Grant
    Filed: October 30, 2003
    Date of Patent: October 31, 2006
    Assignee: WiSys Technology Foundation, Inc.
    Inventor: Daniel S. McGuire
  • Publication number: 20040256081
    Abstract: Disclosed is a mold material for metal casting capable of suppressing the deterioration of cast metal. The mold material for metal casting contains hemihydrate gypsum and a heat resistant material, wherein an oxoacid salt of phosphorus, insoluble in water, is contained in the mold material.
    Type: Application
    Filed: June 15, 2004
    Publication date: December 23, 2004
    Inventor: Daisuke Kato
  • Patent number: 6808010
    Abstract: A method for treating an unfired, molded ceramic core comprises placing an unfired (green) ceramic core having a thermosetting and/or thermoplastic binder on at least one setter, placing the setter and the green ceramic core thereon on a conveyor, conveying the setter and the green core through the heating oven to heat the setter and the green ceramic core to an elevated superambient temperature at or above a softening temperature of the binder present in the green core. Heating of the green ceramic core in this manner conforms the core to a surface of the setter to reduce distortion of the core and improve yields of cores that are within preselected dimensional tolerances.
    Type: Grant
    Filed: March 13, 2001
    Date of Patent: October 26, 2004
    Assignee: Howmet Research Corporation
    Inventors: Bobby A. Dixon, Jennifer A. Holt
  • Patent number: 6779590
    Abstract: Methods for making molding casts by a process typically referred to as “investment casting” using a novel composition is described. The composition is a phosphate bonded material that contains mono-ammonium phosphate (MAP), magnesium oxide and silica filler (quartz, cristobalite, or a mixture thereof). It has been discovered that controlling the amount and ratio of these components has a significant impact on gas permeability (porosity), set time, cast smoothness and cast softness. The most outstanding feature of the new investments is the short mold fabrication and processing time that they allow due to their high gas permeability. The investments can be placed in a burn out furnace while still wet and can be heated rapidly to the firing temperature. The casts can be broken by sandblasting the casts with glass beads. Molds made from the casts have smooth surfaces indicating that the casts are free of visible inclusions and other defects.
    Type: Grant
    Filed: March 10, 2003
    Date of Patent: August 24, 2004
    Assignee: Den-Mat Corporation
    Inventors: Rachel R. Pineda, Thomas C. Chadwick
  • Patent number: 6769475
    Abstract: The present invention relates to improvements in and relating to investment casting. In particular, the invention provides a method of investment casting, comprising the steps of mixing a binder, a refractory material, and a quantity of water-insoluble organic fibres to form a slurry; coating an expendable pattern with a coat of said slurry; and drying said coat or allowing said coat to dry to form a shell. The present invention further provides a refractory slurry for use in the method of the invention, and a kit of ingredients for putting the method of the invention into effect.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: August 3, 2004
    Inventors: Richard Dudley Shaw, Daniel James Duffey
  • Patent number: 6755237
    Abstract: A method of investment casting is disclosed, which comprises the preparation of a refractory slurry by mixing a binder, a refractory material, and a quantity of water-insoluble organic fibres, and the application of one or more coats of this slurry to an expendable pattern, so as to build up a shell. It has been found that each coat of the slurry thus formed is surprisingly thick, and that a relatively short drying time is required for each coat, hence enabling a shell of desirable thickness to be rapidly built in a small number of “dipping cycles”. The invention also encompasses a kit of ingredients for putting the method of the invention into effect; a shell produced in accordance with this method; and a refractory slurry for use in this method.
    Type: Grant
    Filed: October 22, 2002
    Date of Patent: June 29, 2004
    Inventors: Daniel James Duffey, Richard Dudley Shaw
  • Patent number: 6676381
    Abstract: A method and apparatus for casting a near-net-shape article from a high temperature material, such as a refractory metal intermetallic composite material. The apparatus includes: a means for forming a molten material comprising at least one of a metal and an alloy; a means for pouring the molten material; a mold assembly comprising a solid shell having a face coat interposed between the solid shell and molten material; and a heater assembly for maintaining the solid shell at a temperature. The molten material solidifies within the solid shell to form a near-net shape of the article. The near-net shape article may be a turbine assembly component, such as, but not limited to, a vane or airfoil.
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: January 13, 2004
    Assignee: General Electric Company
    Inventors: Pazhayannur Ramanathan Subramanian, Melvin Robert Jackson, Paul Leonard Dupree, Bernard Patrick Bewlay, Theodore McCall Evenden
  • Patent number: 6364000
    Abstract: A ceramic investment shell mold is reinforced with a carbon based fibrous reinforcement having an extremely high tensile strength that increases as the mold temperature is increased especially within the range of casting temperatures employed for casting large directionally solidified industrial gas turbine components. The carbon based fibrous reinforcement is wrapped or otherwise positioned around the repeating ceramic slurry/stucco layers forming the intermediate thickness of the shell mold wall. The reinforced shell mold can be used to cast large directionally solidified industrial gas turbine components with accurate dimensional control.
    Type: Grant
    Filed: September 23, 1997
    Date of Patent: April 2, 2002
    Assignee: Howmet Research Corporation
    Inventors: Rajeev V. Naik, John Corrigan
  • Patent number: 6345663
    Abstract: A method for fabricating a fired ceramic article, a green product, and a fired ceramic article, all for use as a core in the investment casting of directionally solidified eutectic and superalloy material. A ceramic slurry is prepared of alumina, aluminum and a solution of a polymerizable binder in a liquid. The slurry is extruded under low pressure into a closed cavity to form a gelled green product which is subsequently heated in an oxygen-containing atmosphere, wherein the oxygen reacts with the aluminum in the green product to form alumina which advantageously causes an increase in volume of the green product which counters the shrinkage effects of heating.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: February 12, 2002
    Assignee: General Electric Company
    Inventors: Frederic Joseph Klug, Robert Arthur Giddings
  • Patent number: 6302186
    Abstract: A disposable plunger for use in a pressing furnace for the fabrication of dental restorations. The plunger is fabricated of a refractory investment material such as gypsum-bonded, phosphate-bonded or ethyl silicate-bonded investment materials. The plunger is fabricated by known casting methods. The mold used for making the plunger can be supplied by a manufacturer of molds or can be easily made by using an alumina or similar plunger as a model. Laborious cleaning and grinding are not required with plungers herein described. Cracking problems that occur with prior art plungers are decreased, if not completely eliminated.
    Type: Grant
    Filed: November 1, 1999
    Date of Patent: October 16, 2001
    Assignee: Jeneric/Pentron, Inc.
    Inventor: Patricia E. Vidal
  • Patent number: 6257316
    Abstract: A process for rapidly forming a ceramic shell mold on an expendable pattern is disclosed. The process entails use of refractory slurries which include a large particle size colloidal silica sol binder. The colloidal silica sol binder has an average particle size of about 40 nanometers, i.e., about 3-4 times larger than colloidal silica sol binders heretofore employed in manufacture of ceramic shell molds. The use of the large particle sols yields unfired ceramic shell molds which have about 40% to about 70% greater unfired strengths compared to ceramic shells made with prior art small particle size silica sols. Prime coats and refractory back-up coats which use the large particle size sol dry about 30% to about 40% faster than prime coats and back up coats which employ the smaller particle size silica sols of the prior art.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: July 10, 2001
    Assignee: Bontrock Industries, Inc.
    Inventor: John Vandermeer
  • Patent number: 6152211
    Abstract: A method for fabricating a fired ceramic article, a green product, and a fired ceramic article, all for use as a core in the investment casting of directionally solidified eutectic and superalloy material. A ceramic slurry is prepared of alumina, aluminum and a solution of a polymerizable binder in a liquid. The slurry is extruded under low pressure into a closed cavity to form a gelled green product which is subsequently heated in an oxygen-containing atmosphere, wherein the oxygen reacts with the aluminum in the green product to form alumina which advantageously causes an increase in volume of the green product which counters the shrinkage effects of heating.
    Type: Grant
    Filed: December 31, 1998
    Date of Patent: November 28, 2000
    Assignee: General Electric Company
    Inventors: Frederic Joseph Klug, Robert Arthur Giddings
  • Patent number: 6109332
    Abstract: A technique for smoothing and otherwise changing the surfaces of porous bodies, such as ceramic molds, made using layer manufacturing processes, such as three dimensional printing processes. The surface finish of the mold can be smoothed by casting a slip of fine particles onto the surface to form a generally level, and preferably non-conformal, coating on the surfaces. In general, the fine particles of the slip are caused to be filtered out from the liquid, so that the fine particles come to rest at or near the surface of the body formed. They are typically, preferentially drawn toward concave regions of the surface, as compared to convex regions, thereby forming a non-conformal coating. Furthermore, other surface properties can be changed by tailoring the slip to produce those properties. The coating can be applied to external surfaces, and internal surfaces, such as would become the surface against which a molded part would be formed.
    Type: Grant
    Filed: September 28, 1998
    Date of Patent: August 29, 2000
    Assignee: Massachusetts Institute of Technology
    Inventors: Emmanuel M. Sachs, Michael J. Cima, James F. Bredt, Satbir Khanuja
  • Patent number: 6024163
    Abstract: Investment casting shells, methods for their manufacture and methods for casting metals and alloys using such shells are disclosed. One feature of the shells is that the facecoat plus interior backup layers are purposefully designed to have substantially similar coefficients of thermal expansion to the seal dip layers. This helps reduce the occurrence of dimensional casting defects caused by differential thermal expansions of the layers comprising the shell. One embodiment of such a shell comprises a facecoat, plural interior backup layers and plural intermediate backup layers wherein at least one of the plural intermediate backup layers comprises a material capable of undergoing a volumetric transformation during cool down, and wherein the seal-dip layers have a coefficient of thermal expansion that varies from the coefficient of thermal expansion of the facecoat and interior backup layers by less than about 10 percent.
    Type: Grant
    Filed: January 7, 1997
    Date of Patent: February 15, 2000
    Assignee: Precision Castparts Corp.
    Inventors: Mark Edwin Springgate, Douglas Gene Nikolas, David H. Sturgis, Mehrdad Yasrebi
  • Patent number: 6000457
    Abstract: A process for rapidly forming a ceramic shell mold on an expendable pattern is disclosed. The process entails use of refractory slurries which include a large particle size colloidal silica sol binder. The colloidal silica sol binder has an average particle size of about 40 nanometers, i.e., about 3-4 times larger than colloidal silica sol binders heretofore employed in manufacture of ceramic shell molds. The use of the large particle sols yields unfired ceramic shell molds which have about 40% to about 70% greater unfired strengths compared to ceramic shells made with prior art small particle size silica sols. Prime coats and refractory back-up coats which use the large particle size sol dry about 30% to about 40% faster than prime coats and back up coats which employ the smaller particle size silica sols of the prior art.
    Type: Grant
    Filed: June 26, 1998
    Date of Patent: December 14, 1999
    Assignee: Buntrock Industries, Inc.
    Inventor: John Vandermeer
  • Patent number: 5947187
    Abstract: Ceria is used to assure release between a metal workpiece and associated forming tooling in forming operations conducted at temperatures of 1500.degree. F. (816.degree. C.) and above.
    Type: Grant
    Filed: August 18, 1997
    Date of Patent: September 7, 1999
    Assignee: The Boeing Company
    Inventors: Kay Y. Blohowiak, Charles W. Newquist
  • Patent number: 5927379
    Abstract: Methods and compositions for forming shells for investment casting and methods for casting metal articles using the shells are described. One embodiment of the method comprises serially immersing a pattern in at least one, and perhaps several different slurries, each of which slurries comprises refractory material and from about 0 to about 30 volume percent inorganic binder. This forms a facecoat and plural refractory backup layers about the pattern, the facecoat and at least one backup layer defining a shell. The facecoat and/or the shell is then infiltrated with a binder. Infiltrating the shell with a binder is a key feature of the present invention. Infiltration refers to any process whereby a binder can be introduced into the facecoat and/or the subsequent layers built up about the shell.
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: July 27, 1999
    Assignee: PCC Structurals, Inc.
    Inventors: Mehrdad Yasrebi, David Howard Sturgis, William Warren Kemp, Mark Edwin Springgate, Douglas Gene Nikolas
  • Patent number: 5811476
    Abstract: Improved thermoplastic pattern-forming compositions for investment casting processes. The compositions comprise a blend of a thermoplastic pattern-forming material and from about 5 to about 70% by weight of an aqueous gel that is substantially uniformly dispersed throughout the thermoplastic pattern-forming composition. The aqueous gel comprises water and a gellant. The thermoplastic composition may also contain another component in the form of a filler material.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: September 22, 1998
    Inventor: Paul Solomon
  • Patent number: 5766329
    Abstract: A calcia mold facecoat is applied to a mold for casting parts composed of reactive metals such as titanium and titanium aluminide. The facecoat is composed of a calcium carbonate based slurry comprising a dense grain calcium carbonate powder and an aqueous based binder. It is applied to a wax or plastic pattern used in the lost wax process for fabricating a casting shell. The mold is built using multiple dipping of alumina-silicate slurries, and then fired at high temperatures in an oxygen rich environment. The metal part is cast before the fired mold can cool below about 800.degree. C. Organometallic based slurry binders are avoided and significant cost savings are realized owing to the benign nature of the aqueous based suspensions with respect to the environment.
    Type: Grant
    Filed: May 13, 1996
    Date of Patent: June 16, 1998
    Assignee: AlliedSignal Inc.
    Inventors: Jerry Capriotti LaSalle, Anthony Joseph Fanelli, Eoin Joseph Barry, Brian Jeffrey Snow
  • Patent number: 5630465
    Abstract: Mold coatings that are relatively unreactive with titanium and titanium alloys during casting are prepared from yttria slurries, which may contain other refractory materials, an acid and an inert organic solvent.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: May 20, 1997
    Assignee: Remet Corporation
    Inventor: Roy C. Feagin
  • Patent number: 5629369
    Abstract: The invention relates to a water based binder for use in a slurry for investment casting. The binder includes a mixture of a colloidal silica sol and at least one latex polymer. The latex polymer is preferably an acrylic latex or a styrene butadiene polymer (or a combination of these) which reduces the processing time between dips during shell mold making for investment casting. The latex polymer further lowers a critical concentration point or gelation point of the colloidal silica sol. The binder may be used as a primary binder or a backup binder in the shell mold making process. To make the slurry, the binder is combined with at least one refractory powder, preferably a refractory powder selected from the group of: aluminosilicates, fused silica, quartz silica, alumina, zircon, and zirconia.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: May 13, 1997
    Inventor: Manuel Guerra, Jr.
  • Patent number: 5611848
    Abstract: This invention provides a process for preparing a refractory molded article comprising the steps of (a) forming a molded article matrix from an aggregate and the first binder, (b) impregnating the molded article matrix formed in step (a) with the second binder consisting of an alcoholic solution of one kind or two or more kinds of metal alkoxides selected from alkoxides of metals of Group 4A or Group 4B (excepting carbon) and Group 3A or Group 3B of the periodic table and their partial hydrolysates and an alkaline compound of alkali metal or alkaline earth metal (one kind or a mixture of two or more kinds selected from alkoxides, hydroxides and salts of the metal) and (c) drying and firing the molded article matrix at high temperature and also provides a binder for the preparation of such refractory molded article.
    Type: Grant
    Filed: July 16, 1996
    Date of Patent: March 18, 1997
    Assignees: Cadic Corporation, KSP Inc., Tama Chemicals Co., Ltd.
    Inventors: Nobuyoshi Sasaki, Tetsuya Yokokawa, Yoshikazu Hashimoto, Yoshiro Ohta, Hideo Sekiguchi
  • Patent number: 5391606
    Abstract: Emissive compositions are described that can be applied as a coating to the surface of an investment casting mold to increase or decrease the rate of cooling of a casting within the mold. A coating that decreases the rate of cooling of an investment casting within an investment casting mold may comprise a compound having an emissivity less than the emissivity of the mold; a high temperature glass-forming material and a solvent to make a slurry. Similarly, a coating that increases the rate of cooling may comprise a compound having an emissivity greater than the emissivity of the mold; a low temperature glass-forming material and a solvent to make a slurry. Also disclosed in a method of investment casting wherein an emissive composition is applied to the investment casting mold.
    Type: Grant
    Filed: October 4, 1993
    Date of Patent: February 21, 1995
    Assignee: Nalco Chemical Company
    Inventor: Ronald S. Doles
  • Patent number: 5391341
    Abstract: For the manufacture of quickly drying dip coats whose drying time is comparable to the drying time of shells produced on the basis of alcoholic binders, the process uses as a binder for the dip a dispersion of aqueous colloidal silica sol to which synthetic high polymers and/or an emulsion from the group of silicon-organic compounds is formed which after drying is impermeable to water but permeable to water vapor.
    Type: Grant
    Filed: January 17, 1992
    Date of Patent: February 21, 1995
    Assignees: Heinrich Ballewski, Herbert Graf, Wolfgang Grossmann
    Inventors: Heinrich Ballewski, Herbert Graf, Wolfgang Grossmann
  • Patent number: 5238976
    Abstract: The present invention provides methods for treating reclaimed sand obtained from dismantled foundry molds and cores which contain a cured binder derived from an ester cured alkaline phenolic resin. Treatment of the reclaimed sand with a silane solution, particularly an aqueous solution, enhances the tensile strengths of foundry molds and cores produced therefrom beyond those obtained with untreated reclaimed sand. Methods for producing foundry cores and molds which incorporate such a treatment process are also provided by this invention as are raw batch formulations.
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: August 24, 1993
    Assignee: Borden, Inc.
    Inventor: S. Raja Iyer
  • Patent number: 5221336
    Abstract: Reactive metals, such as titanium or nickel-chrome superalloys containing rare earths, are cast with mold and/or core surface areas formed from an improved slurry. The improved slurry contains yttria to form an inert surface which is exposed to the molten reactive metal. In order to prevent premature gelation of the slurry, the forming of defects in the mold and/or core surface areas, and the forming of defects in the cast article, the slurry contains a source of hydroxyl ions. The source of hydroxyl ions is sufficient to result in the slurry having a pH of at least 10.2 six days after initially mixing the slurry. The source of hydroxyl ions may be a metal alkali or an organic hydroxide. It is believed that the source of hydroxyl ions functions as a hydration suppressant for the yttria to prevent premature gelation of the slurry. The slurry contains a silicon oxide (SiO.sub.2) to alkali ratio which is equivalent to a silicon oxide to sodium oxide (Na.sub.
    Type: Grant
    Filed: May 14, 1990
    Date of Patent: June 22, 1993
    Assignee: PCC Airfoils, Inc.
    Inventor: Robert A. Horton
  • Patent number: 5004039
    Abstract: Refractory compositions comprising an acid stabilized aqueous zirconia sol and an active refractory material in an amount effective to gel said sol. A relatively non-active refractory material may also be present. The refractory mix can be made into molded articles or used to form casting molds. Methods of making fired refractory molds and methods of metal casting are disclosed.
    Type: Grant
    Filed: March 9, 1989
    Date of Patent: April 2, 1991
    Assignee: Remet Corporation
    Inventor: Roy C. Feagin
  • Patent number: 4925492
    Abstract: A fired ceramic core for use in aluminum investment casting, which will withstand steam autoclaving and which may be rendered water disruptible; comprising from about 20 to 50% by weight of one or more water soluble salts, together with inert ceramic fillers selected to meet desired thermoexpansion compatability for the shell with which said core is to be used; said core being vacuum impregnated with ethyl silicate and a cured phenolic resin.
    Type: Grant
    Filed: September 21, 1987
    Date of Patent: May 15, 1990
    Assignee: The Interlake Corporation
    Inventors: Anant H. Kelkar, Frank A. Capodicasa, Jerry G. Weinstein
  • Patent number: 4787439
    Abstract: The invention concerns a composition for making a coating consisting essentially of a refractory material selected from the group consisting of yttrium oxide, zirconium oxide, fused yttrium oxide, fused zirconium oxide, fused stabilized zirconium oxide, and fused mixtures of zirconium oxide and yttrium oxide; and a sufficient amount of an yttria sol binder. The composition can be used to prepare refractory materials, casting and core molds.
    Type: Grant
    Filed: November 24, 1986
    Date of Patent: November 29, 1988
    Assignee: Remet Corporation
    Inventor: Roy C. Feagin
  • Patent number: 4703806
    Abstract: An yttria-based slurry comprising a dense grain yttria powder and a non-aqueous-based binder is used as a mold facecoat and corecoat for investment casting of reactive metals such as titanium and titanium alloys.
    Type: Grant
    Filed: July 11, 1986
    Date of Patent: November 3, 1987
    Assignee: Howmet Turbine Components Corporation
    Inventors: Eliot S. Lassow, Paul R. Johnson, Sidney R. Whitaker, Manuel Guerra, Jr.
  • Patent number: 4700768
    Abstract: There is disclosed a mould for lost pattern casting. The shell of the mould comprises a graphite coating and a hydrocarbon binder. The binder comprises a polyol with at least three alcohol functions such as pentaerithritol.
    Type: Grant
    Filed: May 23, 1986
    Date of Patent: October 20, 1987
    Assignees: U.C.P.I. Societe pour l'Utilisation des Ceramiques et des Platres dans l'Industrie, Messier Fonderie D'Arudy
    Inventors: Georges Broihanne, Pierre Magnier
  • Patent number: 4660623
    Abstract: A thin shell ceramic mould for use in metal casting is formed by applying a thin coating of a suitable material and binder to an expandable pattern, e.g. expanded polystyrene, having a density of about 30 to 50 kg/cu.m. The coated pattern is subjected to heat at a temperature of about 1000.degree. C. for 10 minutes to burn out the pattern and cure the coating. The ceramic shell is made just thick enough to be handled.
    Type: Grant
    Filed: January 16, 1984
    Date of Patent: April 28, 1987
    Inventor: Michael C. Ashton
  • Patent number: 4624898
    Abstract: A process is disclosed for providing a refractory composition on a surface. In the process an acidic hybrid binder composition and a basic colloidal silica sol composition are provided. The surface is coated with the acidic hybrid binder composition and the colloidal silica sol composition so that each colloidal silica sol composition coat contacts an acidic hybrid binder composition coat to form alternating layers of the acidic hybrid binder composition and the colloidal silica sol composition. Each acidic hybrid binder composition layer and each colloidal silica sol layer are dried prior to coating with the alternating layer to a sufficient hardness such that lift-off of the applied coatings from the surface is inhibited when a subsequent coating step is performed. A refractory laminate composition is also disclosed which comprises a plurality of layers of hardened acidic hybrid binder composition alternating with a plurality of layers of hardened basic colloidal silica sol composition.
    Type: Grant
    Filed: March 22, 1985
    Date of Patent: November 25, 1986
    Assignee: Harborchem, Inc.
    Inventors: John R. Moore, Stephen Maybaum
  • Patent number: 4604142
    Abstract: An investment material for dental casting comprises 100 parts by weight of a mixture of hemihydrate gypsum, quartz and/or cristobalite and 2 to 5 parts by weight of natural starch optionally with 0.1 to 1.0 part by weight of soluble starch.
    Type: Grant
    Filed: June 10, 1985
    Date of Patent: August 5, 1986
    Assignee: G-C Dental Industrial Corp.
    Inventors: Hiroshi Kamohara, Shohei Hayashi, Nobukazu Ohi