Abstract: This invention relates to foundry binder systems, which cure in the presence of sulfur dioxide and an oxidizing agent, comprising (a) an epoxy resin; (b) an ester of a fatty acid; (c) an effective amount of a oxidizing agent, and (d) no ethylenically unsaturated monomer or polymer. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings, particularly ferrous castings.

Abstract: Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with a refractory metal such as W or Re or a refractory metal carbide such as TaC or HfC. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with titanium carbide via either chemical deposition or plasma assisted chemical vapor deposition, magnetron sputtering or sputtering. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

Abstract: An improved phosphate-type refractory investment material and method for making solid investment molds especially useful for casting high melting point metals and alloys, such as platinum and the like. The material consists essentially of one or more phosphate salts, a water soluble acidic constituent, and refractory powder. The material can be prepared as a dry powder blend which is easily shipped to the user and mixed with water at the time of investing the flask. Alternatively, the salt and/or acidic constituent can be combined with the refractory powder at the time of mixing with water.

Abstract: This invention relates to polyisocyanate compositions comprising (a) polyisocyanate, and (b) a monomeric carbodiimide. The polyisocyanate compositions are particularly useful in phenolic urethane foundry binder systems. The invention also relates to foundry mixes prepared with (a) a phenolic urethane binder containing the polyisocyanate composition, and (b) a foundry aggregate, as well as foundry shapes prepared by the no-bake and cold-box processes, which are used to make metal castings.

Abstract: The invention provides a method with which high-quality complex-shaped castings can be manufactured and with which, after the end of the casting process, the casting mould parts can be easily removed out of or from the casting without any risk.

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.

Abstract: The invention relates to investment casting shell molds and their method of manufacture. The method entails mixing fiber such as ceramic refractory fiber and organic fiber with ceramic filler to form a dry blend. The dry blend is mixed with a binder sol such as colloidal silica sol to form slurry. An expendable preform is dipped into the slurry, stuccoed and dried. This step is repeated until a ceramic shell of a desired thickness is formed over the expendable preform. The expendable preform then is removed, and the green ceramic shell is fired. Molten metal then may be poured into the shell to form a metal casting.

Abstract: A method of making a spray formed article includes the steps of providing a sand pattern and spraying metal material toward the sand pattern to form the desired article. The sand pattern is made from a sand molding composition comprising refractory materials and binder. The refractory material comprises at least about 15 weight percent alumina, based on the total weight of the refractory material.

Abstract: Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with titanium carbide. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with titanium carbide via either chemical deposition or plasma assisted chemical vapor deposition, magnetron sputtering or sputtering. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

Abstract: Methods for making various metallic alloys such as nickel, cobalt and/or iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent casting of the melt in the graphite molds under vacuum or low partial pressure of inert gas are provided, the molds having been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding.

Abstract: Methods for making various titanium base alloys and titanium aluminides into engineering components such as rings, tubes and pipes by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent centrifugal casting of the melt in the graphite molds rotating along its own axis under vacuum or low partial pressure of inert gas are provided, the molds having been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding, the said molds either revolving around its own horizontal or vertical axis or centrifuging around a vertical axis of rotation.

Abstract: Disclosed is a method for manufacturing a disintegrative core for use in high pressure casting. The disintegrative core can be applied where a light metal such as an aluminum alloy or magnesium alloy is subjected to high pressure casting, such as die casting or squeeze casting and is manufactured from a water-soluble salt which is high in latent heat and ranges, in melting point, from 280 to 520° C. and, in heat transfer coefficient (&kgr;), from 9.8×10−2 to 1.2×10 W/m·° C. The water-soluble salt, alone or in combination with a fine hard powder, is melted and solidified in a core mold. Alternatively, the melt is processed into a fine powder which is then molded in a core mold. The method can be applied for the manufacture of complex shapes of cores. Also, disclosed is a method for extracting such a core from a high pressure molded product.

Abstract: A method and apparatus for the lost pattern casting of metals employs an erodable mold including a particulate material and a binder. An erodable backing or coating may be used to support the erodable mold. After a molten metal casting is poured in the mold, the erodable backing and the mold are contacted with a solvent. This cools the molten metal so that it at least partially solidifies to form a casting. At least a part of the mold is removed. Also, the coating or backing may be removed.

Abstract: Coating foundry sand with a thin layer of an oxidation-promoting catalyst. Preferred catalysts comprise ferric and cupric oxides. The catalysts promote the oxidation of any polymeric binder or residues admixed with the sand. The sand is coated by wetting the grains with a solution of a catalyst precursor, drying the sand and baking the sand in air to convert the precursor to the catalyst.

Abstract: An improved phosphate-type refractory investment material and method for marking solid investment molds especially useful for casting high melting point metals and alloys, such as platinum and the like. The material consists essentially of one or more phosphate salts, one or more water soluble organic acids, and refractory powder. The material can be prepared as a dry powder blend which is easily shipped to the user and mixed with water at the time of investing the flask. Alternatively, the salt and/or organic acid can be combined with the refractory powder at the time of mixing with water.

Abstract: Methods for making various titanium base alloys and titanium aluminides into engineering components such as rings, tubes and pipes by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent centrifugal casting of the melt in the graphite molds rotating along its own axis under vacuum or low partial pressure of inert gas are provided, the molds having been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding, the said molds either revolving around its own horizontal or vertical axis or centrifuging around a vertical axis of rotation.

Abstract: Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with titanium carbide. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with titanium carbide via either chemical deposition or plasma assisted chemical vapor deposition, magnetron sputtering or sputtering. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

Abstract: Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with pyrolytic graphite. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with pyrolytic graphite via a chemical deposition process. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

Abstract: A mold for the casting of metals including an aggregate comprising a refractory particulate material and a soluble binder which provides for minimal heat transfer between the mold and the molten metal during filling. The aggregate preferably includes at least a proportion of particulate material having a heat diffusivity at least as low as silica sand to reduce the chilling effect of the mold. The mold is removed from the casting the action of a solvent, which simultaneously cools and solidifies the casting at a maximum rate. Processes for forming the mold and the casting of metals using the mold are also disclosed.

Abstract: Methods for making various titanium base alloys and titanium aluminides into engineering components such as rings, tubes and pipes by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent centrifugal casting of the melt in the graphite molds rotating along its own axis under vacuum or low partial pressure of inert gas are provided, the molds having been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding, the said molds either revolving around its own horizontal or vertical axis or centrifuging around a vertical axis of rotation.

Abstract: This invention relates to erosion resistant foundry binder systems, which will cure in the presence of sulfur dioxide and a free radical initiator, comprising (a) an epoxy resin; (b) a multifunctonal acrylate; (c) a phenolic resin that is soluble in (a) and (b); and (d) an effective amount of a free radical initiator. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings.

Abstract: This invention relates to foundry binder systems, which will cure in the presence of sulfur dioxide and a free radical initiator, comprising (a) an epoxy novolac resin; (b) preferably a bisphenol F; (c) an acrylate; and (d) an effective amount of a free radical initiator. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings.

Abstract: A molding body for the production of a cavity in a metal casting such as a piston of an internal combustion engine, the molding body being composed of calcium silicate fibers held together in a solid form by a soluble binding agent.

Abstract: Methods for making various metallic alloys such as nickel, cobalt and/or iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent casting of the melt in the graphite molds under vacuum or low partial pressure of inert gas are provided, the molds having been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding.

Abstract: A ceramic mould slurry is disclosed for forming moulds and metal castings of improved surface quality. The slurry comprises a binder, a gelling agent, a first refractory material having a density of &rgr;1 and a mean particle size of &agr;1, and a second refractory material having a density of &rgr;2 and a mean particle size of &agr;2, wherein &rgr;1>&rgr;2 and &agr;1<&agr;2. The denser refractory material migrates downward through the slurry toward the upward-facing mould surface, thereby allowing formation of a smooth and accurate surface.

Abstract: A process for forming a mould or a core for casting molten metal by machining (eg cutting or drilling) to the desired shape a bonded particulate refractory material wherein the shear strength of the refractory particles is less than the shear strength of the bonds between the particles. The preferred particulate is aluminosilicate microspherers (eg “flyash floaters”) and the binder is preferably based on silica (eg fumed silica/sodium hydroxide). The bonded particulate material is easily machined to form accurately dimensioned moulds or parts thereof.

Abstract: A ceramic mould slurry is disclosed for forming moulds and metal castings of improved surface quality. The slurry comprises a binder, a gelling agent, a first refractory material having a density of &rgr;1 and a mean particle size of &agr;1, and a second refractory material having a density of &rgr;2 and a mean particle size of &agr;2, wherein &rgr;1>&rgr;2 and &agr;1<&agr;2. The denser refractory material migrates downward through the slurry toward the upward-facing mould surface, thereby allowing formation of a smooth and accurate surface.

Abstract: A sand casting foundry composition reduces thermal defects that cause veining in metal parts cast from sand casting foundry shapes formed from the foundry composition. Foundry sand grains are mixed substantially uniformly with thermally collapsible clay mineral particles, and a curable binder coats the sand grains and the thermally collapsible clay mineral particles to establish core and mold foundry shapes used to cast the metal part. Anti-veining capability occurs because the thermally collapsible clay mineral particles exhibit an inherent characteristic of crystal structure collapse upon exposure to temperatures encountered in casting the metal part. The crystal structure collapse yields space which is consumed by thermal expansion of the sand grains in the foundry composition. This compensatory effect avoids the creation of mechanical forces and stresses within the foundry shape that cause the cracks and fissures in the foundry shape that lead to veining.

Abstract: This invention relates to foundry binder systems, which will cure in the presence of sulfur dioxide and a free radical initiator, comprising (a) an epoxy resin; (b) an acrylate; (c) an alkyl silicate; and (d) an effective amount of a free radical initiator. The foundry binder systems are used for making foundry mixes. The foundry mixes are used to make foundry shapes (such as cores and molds) which are used to make metal castings, particularly ferrous castings.

Abstract: The molding sand comprises hollow microspheres of aluminum silicate, preferably with an aluminum content between 15 and 45% by weight, a wall thickness between 3 and 10% of the particle diameter and a particle size between 10 and 350 &mgr;m. These sands are useful to manufacture low density cores with good “veining” and penetration characteristics, moreover maintaining the mechanical properties of the core obtained. These cores are useful in the manufacture of iron casting.

Abstract: Irregularly shaped mold-core assemblies are retained for casting within a thin-wall container by solid particulate material. In the process, the mold and core elements are formed from the core sand. After the mold and core elements, both of which are formed from core sand, are assembled, the assembly is placed in a container large enough to provide space around the assembled mold and core elements, and solid particulate material is placed in the space around the mold-core assembly to hold the assembled mold and core elements together during pouring of the molten iron alloy into the mold-core assembly and the cooling period, during which the molten iron alloy solidifies to form the casting. After the casting is formed, the solid particles and the core sand from the mold elements and core elements are recovered, processed and reused in further casting operations.

Abstract: Molds are fabricated having a substrate of high density, high strength ultrafine grained isotropic graphite, and having a mold cavity coated with pyrolytic graphite. The molds may be made by making the substrate (main body) of high density, high strength ultrafine grained isotropic graphite, by, for example, isostatic or vibrational molding, machining the substrate to form the mold cavity, and coating the mold cavity with pyrolytic graphite via a chemical deposition process. The molds may be used to make various metallic alloys such as nickel, cobalt and iron based superalloys, stainless steel alloys, titanium alloys and titanium aluminide alloys into engineering components by melting the alloys in a vacuum or under a low partial pressure of inert gas and subsequently casting the melt in the graphite molds under vacuum or low partial pressure of inert gas.

Abstract: An impregnated fired porous alumina-based ceramic core for use in an investment shell mold in the casting of molten metals and alloys wherein the core is impregnated with yttria to improve core creep resistance at elevated casting temperatures and times.

Abstract: A ceramic casting shell mold having a pre-selected shape comprises alternate, repeating layers of a ceramic coating material and a ceramic stucco, defining a total thickness of the shell mold; and a ceramic-based reinforcing sheet disposed in the alternate, repeating layers of coating material and stucco at an intermediate thickness. The ceramic-based reinforcing sheet comprises a one-piece monolithic, integral body, which comprises a pattern of holes that enhance bonding between the ceramic-based reinforcing sheet and adjacent ones of the alternate, repeating layers of ceramic coating material. The ceramic-based reinforcing sheet conforms to the shape of the mold and providing structural reinforcement to the mold.

Abstract: Irregularly shaped mold-core assemblies are retained for casting within a thin-wall container by solid particulate material. In the process, the mold and core elements are formed from the core sand. After the mold and core elements, both of which are formed from core sand, are assembled, the assembly is placed in a container large enough to provide space around the assembled mold and core elements, and solid particulate material is placed in the space around the mold-core assembly to hold the assembled mold and core elements together during pouring of the molten iron alloy into the mold-core assembly and the cooling period, during which the molten iron alloy solidifies to form the casting. After the casting is formed, the solid particles and the core sand from the mold elements and core elements are recovered, processed and reused in further casting operations.

Abstract: Coating foundry sand with a thin layer of an oxidation-promoting catalyst. Preferred catalysts comprise ferric and cupric oxides. The catalysts promote the oxidation of any polymeric binder or residues admixed with the sand. The sand is coated by wetting the grains with a solution of a catalyst precursor, drying the sand and baking the sand in air to convert the precursor to the catalyst.

Abstract: The molding sand comprises hollow microspheres of aluminum silicate, preferably with an aluminum content between 15 and 45% by weight, a wall thickness between 3 and 10% of the particle diameter and a particle size between 10 and 350 &mgr;m. These sands are useful to manufacture low density cores with good “veining” and penetration characteristics, moreover maintaining the mechanical properties of the core obtained. These cores are useful in the manufacture of iron casting.

Abstract: A foundry exothermic assembly is formed by mixing hollow glass microspheres and an inorganic or organic binder with matrix forming constituents including an oxidizable metal, an oxidizing agent, a foundry refractory aggregate and, optionally, a pro-oxidant, and shaping and curing the mixture. The hollow glass microspheres are dispersed and embedded in the assembly matrix.

Abstract: This invention relates to exothermic and insulating sleeve mixes comprising (1) a sleeve composition comprising stabilized hollow aluminosilicate microspheres, and (2) a chemically reactive binder. Sleeves are formed from the sleeve mix and are cured in the presence of a catalyst by the cold-box or no-bake curing process. The invention also relates to a process for casting metal parts using a casting assembly where the sleeves are a component of the casting assembly. Additionally, the invention relates to the metal parts produced by the casting process.

Abstract: An embodiment of the present invention provides a method for improving the tensile strength of foundry cores and molds over what may be conventionally achieved. The use of acidic methylene compounds in binder compositions which include strongly alkaline phenolic resoles results in an ester curable binder that may be used to make foundry cores and molds having significantly greater tensile strengths than are achieved with prior art binders. An embodiment of the present invention provides a composition which includes a phenolic resole having a pH ranging from about 10.5 to about 13.5 and an acidic methylene compound.

Abstract: A metal or metal alloy article is cast using an investment casting mold where the mold facecoat, and perhaps one or more of the mold backup layers, comprises an imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions. The facecoat preferably comprises an intimate mixture of a refractory material and the imaging agent. Intimate mixtures can be produced in a number of ways, but a currently preferred method is to cocalcine the refractory material, such as yttria, with the imaging agent, such as gadolinia. The facecoat also can comprise plural mold-forming materials and/or plural imaging agents. The difference between the linear attenuation coefficient of the article and the linear attenuation coefficient of the imaging agent should be sufficient to allow imaging of the inclusion throughout the article. The metal or metal alloy article is then analyzed for inclusions by N-ray analysis.

Abstract: Insulating sleeve mixes that contain hollow aluminosilicate microspheres, an organic binder, and boric acid and/or a phosphate, and their uses.

Abstract: A ceramic core that includes, prior to core sintering, erbia filler material alone or admixed with a second ceramic filler material, such as alumina, and a binder to provide a core that is relatively non-reactive with superalloys used in the manufacture of turbine blades, dimensionally stable during directional solidification (DS) for extended times, removable by chemcial leaching techniques, and having enhanced X-ray detectable during post-cast inspection operations. After core sintering, the ceramic core has a microstructure comprising an erbia-alumina garnet phase and an unreacted ceramic filler phase (e.g. alumina).

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.

Abstract: A method of constructing a fully dense metal part or a metal mold half for matin with another mold half to form a mold for casting multiple parts. Steps include placing a pattern having critical pattern surfaces in a flask having an open end. The critical pattern surfaces face upward. Other steps involve covering the critical pattern surfaces with a concentrated heat reversible gel solution added to the flask, and cooling the gel solution to form an elastic solid gel mold. Further steps include removing the flask and the pattern from the elastic gel mold, and casting a ceramic mold around the solid gel mold. In other steps the gel mold is liquified for removal from the ceramic mold and the ceramic mold is inverted so that its critical ceramic surfaces face upward.

Abstract: An improved soluble core for die casting metals or metal matrix composites is formed of a mixture of salt and about more than 0 weight % and less than 20 weight % of ceramic material blended together to produce a homogeneous mixture and compacted under pressure to produce a soluble core having little or no porosity. The ceramic material can be in the form of fibers, particulates, whiskers, and/or platelets, and has a melting temperature greater than that of the salt. The core can include a thermally insulating outer ceramic coating to enable the core to withstand higher die casting temperatures than conventional salt cores. The improved soluble core is removable with hot water and/or steam and the core material can be reclaimed for reuse.

Abstract: Thermal expansion defects, i.e. veining, are reduced in iron, steel, and nonferrous castings by adding a lithia-containing material in a sufficient amount to the silica sand mold to provide about 0.001% to about 2.0% of lithia. The addition of lithia is accomplished by adding lithium bearing minerals such as .alpha.-spodumene, amblygonite, montebrasite, petalite, lepidolite, zinnwaldite, eucryptite or lithium carbonate.

Abstract: A combustible carbonaceous composition and method of making a charcoal briquette wherein a finely divided carbonaceous material is combined with an activated carbon and/or an activated graphite (which may be formed in-situ during pyrolysis of the composition by reacting a humic-containing ore with a low VOC-containing carbon and/or graphite). The combustible carbonaceous composition is present in the briquette composition in an amount of about 65% to about 99.9% by weight; a binder is included in the composition in an amount of about 1% to about 15% by weight when forming a charcoal briquette or an igniter log; and the activated carbon and/or activated graphite is present in an amount of about 0.1% to about 20% by weight. The activated carbon and/or activated graphite absorbs most of the VOCs entitled from the combustible carbonaceous material, thereby preventing the VOCs from escaping to the atmosphere.

Abstract: Crushed and graded magnetite ore is mixed with clay to form foundry moulds and cores. These moulds or cores are useful when casting non-ferrous metals or alloys, especially light metals and light-metal alloys.

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.