Abstract: A method of casting a workpiece having internal cavities uses a combination of sand core and lost foam techniques. A core of bonded granular material in the desired configuration of the voids of the workpiece is formed. The core has oppositely facing first and second surfaces with a pattern of channels extending between them. The pattern of the channels is in the desired configuration of walls for the cavities of workpiece. A first foam layer of destructible material is preformed and secured to the first surface of the core overlying one side of the channels. A second foam layer of destructible material is preformed and secured to the second surface of the core, overlying an opposite side of the channels. The assembly is placed in a refractory mold cavity, and granular refractory material is packed around the assembly.

Abstract: A casting includes a heat transfer surface having a plurality of cavities. The plurality of cavities include a density of at least about 25 cavities per square centimeter to about 1,100 cavities per square centimeter resulting in increased surface area and therefore enhanced heat transfer capability. A mold for forming a pattern for molding the casting includes a surface defining a portion of a chamber to which are attached a plurality of particles having an average particle size in a range of about 300 microns to about 2,000 microns.

Abstract: The evaporative casting of molten metals has been shown to produce castings having smooth surfaces with significantly less signs of carbon deposits thereon by using an expandable vinyl aromatic polymer containing a bromine-attached aliphatic or aromatic flame retardant.

Abstract: A vent-forming apparatus for use in metal casting comprises a gas-permeable membrane with a lead-in tube attached to one surface and a breather tube attached to the opposite surface. The vent-forming apparatus may be used to create independent vents in the walls of shell-type molds used in the ceramic shell casting process for lost wax casting of ferrous and non-ferrous alloys. These vents exhaust gasses in the mold cavity to the atmosphere. The vent-forming apparatus also may be used in solid mold investment casting methods or in any other casting method in which venting is desirable or necessary.

Abstract: A casting includes a heat transfer surface having a plurality of cavities. The plurality of cavities include a density of at least about 25 cavities per square centimeter to about 1,100 cavities per square centimeter resulting in increased surface area and therefore enhanced heat transfer capability. Also disclosed is a mold for forming a pattern for molding the casting. The mold includes a surface defining a portion of a chamber to which are attached a plurality of particles having an average particle size in a range of about 300 microns to about 2,000 microns.

Abstract: The method of lost foam casting uses a polystirene foam pattern molded from polystirene beads preexpanded from raw polystirene beads that have a raw bead diameter in the range of about 0.1 to about 0.6 millimeters and that include isopentane as a relatively slow diffusing blowing agent alone, or together with normal pentane as a relatively high diffusing blowing agent, the isopentane being present in an amount of at least about 40% by weight of the total blowing agent of the raw beads to significantly reduce post-molding dimensional pattern shrinkage and to render the molded patterns inherently more dimensionally stable. The patterns can be used directly in the lost foam casting of molten metal without the need for any intermediate pattern dimension-stabilizing treatment.

Abstract: Disclosed is an integral single-cast multi wall structure including a very thin wall and a second thin wall. There is a passageway interposed between the pair of walls of the structure, and a high thermal conductivity member extends into said passageways and thermally couples the walls. The high thermal conductivity member increases the heat transfer between the walls of the structure. The present invention further includes a method for casting an integral structure having very thin walls that utilizes the high thermally conductive member in the casting process to hold the pattern and cores in alignment.

Abstract: Fold defects are reduced or eliminated in lost foam castings by contacting a destructible polymeric pattern surface proximate to which deleterious fold defects comprising unbonded seams are prone to form in the solidifying molten metal with a material that reduces or eliminates fold defects in the casting proximate the pattern surface. The material can comprise a silicone layer that is anti-sticking relative to a gas permeable refractory layer on the pattern or foundry sand directly contacting the pattern surface depending on casting configuration. The pattern is cleaned prior to contact with the material. Lower melt casting temperatures can be used with concomitant improvements in casting microstructure (e.g. finer dendritic arm spacing) and mechanical properties.

Abstract: A method for producing a mold for making an integrally formed three-dimensional truss structure, containing outer top and bottom plane surfaces thereof comprising interconnected rod segments integrally formed at their points of intersection on the outer top and bottom surfaces, the top and bottom surfaces also integrally joined together through additional interconnected rod segments passing through an integrally formed intersection, wherein the additional interconnected rod segments passing through the integrally formed intersection form a three-dimensional continuous array of triangles.

Abstract: Steel bit bodies are manufactured with polystyrene patterns in a lost foam casting process. The patterns are machined in complex shapes that cannot be extractable from reusable, two-piece pattern molds. The patterns are machined in a basic, programmed, five-axis machining process to form multiple copies of a complex pattern body. The process is modified to produce multiple copies of a modified design. Multiple bit patterns of variable forms are produced without an intermediate, reusable pattern mold that would require multiple mold pieces, thus eliminating the time and expense in variation of the bit design. The pattern is machined in a single chucking operation in a machine tool adapted for machining plastics in a three-dimensional global process. The plastic composition and density permit it to be machined into a pattern having relatively small, unsupported structural projections and smooth surface features.

Abstract: A rotatable vehicle brake component having integrally formed teeth adapted for use with a sensor of an anti-lock brake system is disclosed.

Abstract: A structure of solid material for use in making an investment casting mold and a method of making it are disclosed. The structure has a plurality of levels of spaced plates arranged such that in plan view the plates define a plurality of adjoining polygonal formations. The method includes solidifying portions of a body of liquid material to provide a first set of spaced plates, solidifying further portions at different levels to provide at least a second set of plates oriented transversely of plates of the first set. Adjacent sets are interconnected along side edges in essentially point connections.

Abstract: Housing frames for use in electromechanical machines may be advantageously produced using a novel pattern form in a lost foam casting process. The pattern form is made from a cast dissolvable material, and is configured to permit easy modification prior to casting. The pattern form may be adapted to produce footed or footless housing frames, or housing frames of various axial lengths. In addition, the frame area on which a conduit box will be attached can be easily modified prior to casting. After the pattern form has been modified, it is placed in a casting medium of dry particulate material, such as sand. Upon contact with molten metal, the pattern form vaporizes. The molten metal fills the space where the pattern form had been, assuming the desired shape. After the molten metal has cooled to rigidity, the resulting housing frame can be removed from the casting medium.

Abstract: A foamable, ashless investment casting replica composition comprises a foaming compound and a polymer. The foaming compound contains an ammonium salt of a polycarboxylic acid, at least one suspending agent, and may contain at least one carrier resin. During the molding of the replica, the foamed composition avoids shrinkage and thereby maintains its intended shape. In addition, thermal decomposition of the foaming compound yields only volatile gases and therefore leaves no ashes on the interior surface of the ceramic mold.

Abstract: A core for use in a die casting process has a wood fiber material as a main ingredient. The core can be disintegrated by exerting an external force subsequent to the die casting process. The core can also be disintegrated by applying a softening agent to soften it subsequent to the die casting process. Further, the core can be made up of a stack of paper layers that are peelably removable from each other.

Abstract: A method of casting hypereutectic aluminum-silicon alloys in an evaporable foam casting process with the application of pressure during the solidification of the alloy. A pattern is formed from a polymeric material having a configuration of an article to be cast. The pattern is supported in an outer mold and unbounded sand surrounds the pattern and fills the cavities within the pattern. The pattern is contacted with a molten hypereutectic aluminum-silicon alloy containing 16% to 30% silicon and having less than 0.8% copper. The molten alloy decomposes the foam pattern with the vapors of decomposition being entrapped within the interstices of the sand. While the alloy is in the molten state, gas pressure is applied to the alloy in the magnitude of 5 to 12 atmospheres to produce a cast alloy having less than 0.03% porosity and a high cycle fatigue strength greater than 13 KSI.

Abstract: The models comprise an expanded or expansible polymer or copolymer generally used for the fabrication of such models. The polymer or copolymer contains an oxidizing agent comprising a nitroaliphatic compound that accepts expansion without substantial alteration of its oxidizing properties, that does not substantially modify the characteristics of the polymer or copolymer before, during and after expansion, that does not harm the quality of the metal that is cast, and that has a decomposition temperature essentially identical to that of the polymer or copolymer.

Abstract: The pattern material with substantially spherical filler particulates is used to produce investment cast components with improved surface quality, reduced finishing costs, and reduced core breakage. The pattern material comprises substantially spherical particles within the particle size range of about 10 microns to about 70 microns particle diameter, the use of which reduces the number of random, localized surface depressions and pits to improve pattern surface texture and uniformity. Patterns so formed inpart the same improvements to the surface of subsequent investment cast components. The resulting castings exhibit improved as-cast surface finish and reduced random, localized surface pitting, thereby reducing or eliminating expensive post casting surface finishing operations. Moreover, the spherical morphology of the filler particulates reduces injection pressures to fill a pattern die cavity as compared to non-spherical filler particulates.

Abstract: A method of integrating detailed features into a spray formed rapid tool includes the steps of making a model of a desired tool and constructing a ceramic pattern as the inverse of the model. The method also includes the steps of locating at least one detailed feature insert on the ceramic pattern and thermally spraying metal material against the detailed feature insert and ceramic pattern to form the desired tool and embedding the detailed feature insert into the desired tool.

Abstract: An improved method of lost foam casting of aluminum silicon alloys utilizing a pattern formed of an expandable polymeric foam having a decomposition temperature less than 300.degree. C., and a heat of decomposition less than 600 Joules per gram. The foam pattern preferably has a heat of fusion less than 60 Joules per gram and a bulk density in the range of one to four pounds per cubic foot. The lost foam casting procedure has particular use when casting hypereutectic aluminum silicon alloys containing from 16 to 30% silicon, and eliminates the "liquid styrene" defect which occurs when casting such alloys in a lost foam process utilizing conventional polystyrene foam patterns. When casting hypoeutectic aluminum-silicon alloys containing from 5% to 8% silicon, the method eliminates the "fold" defect.

Abstract: The coated pattern is formed from a consumable pattern, preferably polystyrene, and is adapted to be decomposed and replaced by molten metal to form a casting. The improved coating is the dried residue of an aqueous coating formed from water, refractory particles, and from between about 25 wt-% and 75 wt-% organic polymer on a non-volatile solids basis (i.e., dry film basis). Lustrous carbon is reduced when casting iron.

Abstract: Methods are provided for producing investment cast articles, such as orthopedic implants or portions thereof, having at least a partially textured surface that is formed during casting of the article. In an exemplary method, a textured metal casting is produced by creating a heat destructible pattern and spraying the pattern with a texturing material to cause the texturing material to form a textured surface on at least a portion of the pattern. In another embodiment, a textured template is pressed against a heat softenable pattern to provide a textured pattern. With respect to each of these methods, a shell is the created around the textured pattern form a mold, and the pattern is removed from the shell. Molten metal is introduced into the mold and allowed to harden, after which the mold is removed. In yet another embodiment a textured pattern for investment casting is provided by creating a textured model and enveloping it with a resilient material to create a resilient mold.

Abstract: Steel bit bodies are manufactured in a production process that employs polystyrene patterns in a lost foam casting process. The patterns are machined to permit the formation of complex shapes that cannot be reproduced in simple patterns that are extractable from reusable, two-piece pattern molds or dies. The patterns are machined from a billet material according to a basic, programmed, five-axis machining process to form multiple copies of a reproducible complex pattern body. The process is modified to produce multiple copies of a modified design. Machining the complex patterns and producing variations by changing the machine program permit multiple bit patterns of variable forms to be produced without need for building an intermediate, reusable pattern mold that would require multiple mold pieces, thus eliminating the associated time and expense required in the creation of a new pattern mold for each variation of the bit design.

Abstract: The investment casting method uses the lost wax method and involves using a model to form a wax piece in the desired shape such as the shape of the snap element or the shape of two hinge halves, making a tree out of a multitude of the wax pieces, adding slurry and heating to create hard material having spaces shaped like the wax parts and then pouring molten casting material into the spaces in a vacuum environment.

Abstract: A structure of CO.sub.2 -insoluble material has a three-dimensional object of CO.sub.2 -soluble material positioned inside. The object is contacted with a fluid containing carbon dioxide which dissolves the object in the fluid. The fluid is then removed to form a cavity in the structure.

Abstract: A wax article pattern having a cavity corresponding to a cavity in a metal article is provided. The cavity in the wax article pattern is filled with a slurry of ceramic core material. The slurry of ceramic core material is solidified to form a core. The wax article pattern is enclosed by ceramic mold material. The ceramic mold material is solidified to form a mold. The wax pattern is removed from the mold to leave an article mold cavity. The article mold cavity is filled with molten metal which is solidified to form the metal article. A passage in the metal article may be formed by a pin which extends from the wax article pattern into the cavity in the wax article pattern and is enclosed by the slurry of ceramic core material.

Abstract: This invention includes a method, a casting pattern, and an apparatus directed to gasifying residue during metal casting. The method for metal casting includes using a casting pattern that includes an additive that can react with a residue formed as the casting pattern degrades during casting. The casting pattern includes an additive that can react with a residue formed as a result of degradation of the casting pattern during casting. The metal casting apparatus includes a casting pattern having an additive that can react with a residue formed as the casting pattern degrades during casting, and a casting medium in which the casting pattern is at least partially immersed.

Abstract: A method of making a custom, bioimplantable article, such as a joint prosthesis component, is provided using computer aided design, rapid prototyping, and investment casting techniques. The method includes the creation of a data file, using computer aided design (CAD) techniques, that defines a negative or a shell of a portion of a bioimplantable article that is custom configured for a specific arthroplasty patient. The data file for the shell of the custom portion of the bioimplantable article is accessed by a rapid prototyping machine, such as a three-dimensional printer, to create a mold that corresponds to the shell. The mold, generally a heat-resistant ceramic, is positioned relative to an existing, non-custom representation of a bioimplantable article to define a hybrid component. A heat-resistant shell is formed around the hybrid component and the non-custom representation of a bioimplantable article is removed from the shell using heat.

Abstract: A lost foam casting method for the manufacture of scrolls.

Abstract: The investment casting process utilizes an investment assembly that includes one or more vents in each casting mold. Vents facilitate the extraction of the pattern material while preventing expansion of the pattern material to the extent that mold fracture or cracking results. The vents can be formed by incorporating within the patterns of articles to be cast one or more protrusions that cause the pattern to deviate from the size and shape of the article to be cast. After assembly of one or more patterns to a riser to form a cluster, the cluster is coated with a refractory material and the refractory material is removed from the protrusions either before the refractory dries or after the refractory dries, thus producing the vents.

Abstract: An implantable article having on at least a portion of its exterior surface an integral, as-cast macrotextured surface having pores with undercut edge profiles is provided. The integral, as-cast macrotextured surface is able to be formed on the implantable articles by a modified casting process. As part of a casting process, positive models of the articles to be cast, or parts thereof, are formed by stereolithographic techniques. Cavities or molds, representing negative images of the articles to be cast, are then formed by encasing one or more models in a refractory material. The positive models are then extracted by heating and thus melting the material from which they are made. Thereafter, molten casting material can be poured into the resulting mold to obtain the implantable articles.

Abstract: Method of making a rapid tool, comprising: making a plastic pattern of the tool by free form fabrication techniques following a computer aided design, the design having a base and no undercuts taken in a direction perpendicular to base; constructing a ceramic mold as the inverse of the pattern; separating the pattern from the mold by a separating movement in a direction perpendicular to the base to leave a surface defining a casting cavity within the mold; and thermally spraying tool steel particles against the casting cavity surface is a thickness exceeding 1 inch while rapidly cooling the sprayed particles to effect a net shape tool without the need for further working or heat treatment.

Abstract: A dynamoelectric machine having a stator housing or frame made by a lost foam process utilizing a unitary single-piece vaporizable pattern. The stator housing may be made from a molten metal such as cast iron or aluminum, and has an annular wall having integral outwardly extending longitudinal cooling fins, mounting foots pads and a conduit box support pad. The lost foam process enables the cooling fins to have a greater effective cooling fin height to housing diameter ratio and greater effective cooling fin height to housing annular wall thickness ratio than obtained with prior sand casting processes. The greater height fins provide increased strength and rigidity for the annular wall which can be made radially thinner than prior stator housing or frames of similar size. Substantial savings in material and labor are realized by the stator housing.

Abstract: Disclosed herein is a one piece drive shaft housing comprising a casting including an outer surface having an upper end surface, a lower end surface, and an endless side surface extending between the upper and lower end surfaces, an internal cavity extending between the upper and lower end surfaces and adapted to receive a drive shaft and a clutch operated linkage, an internal exhaust gas passage extending between the upper and lower end surfaces and located in spaced relation to the cavity, an internal coolant supply passage extending between the upper and lower end surfaces, an internal idle exhaust passage including a series of expansion chambers and extending between the upper end surface and the endless side surface, and an internal coolant drainage passage extending between the upper and lower end surfaces in heat exchanging relation to the exhaust gas passage.

Abstract: A method of making a heterogeneous metal matrix composite (MMC), and preform therefor. An open cell foam substrate is infiltrated with a slurry of reinforcement particles carried in a vehicle. The vehicle is removed leaving the particles trapped within the interstices of the foam. In one embodiment, the substrate is a fugitive polymer foam which is removed prior to filling the preform with metal. In another embodiment, the substrate is a metal foam which remains with the preform and the MMC after filling with metal.

Abstract: The present invention relates to an improved process for the preparation and fabrication of horseshoes whereby pure titanium or titanium alloys are processed with the exclusion of contaminating gases such as Oxygen, Nitrogen and Hydrogen. The titanium horseshoes have many advantages over the present state of art such as light weight, higher tensile strength, flexible, wearing resistance, abrasion resistance, hypoallergenic, workability, formability, friction-free, physiologically inert, and are easily formed and shaped into the desired configuration.

Abstract: A process for casting a hard-faced cylindrical product such as an automobile camshaft includes the steps of: (a) preparing a composition formed from a molten base metal and an additive in particle form and having a hardness value greater than the hardness value of the base metal; (b) introducing the composition into a flask containing a meltable pattern of a cylindrical product such as an automobile camshaft to be manufactured and encased in sand to allow the composition to melt the pattern and assume the shape of the pattern within the sand; and (c) rotating the flask containing the pattern about the longitudinal axes of both the flask and the pattern as the molten base metal containing the additive in particle form is introduced into the flask to cause particles of the additive entrained in the molten base metal to migrate by centrifugal action to the radial extremities of the pattern and thereby provide a cylindrical product having a hardness value greater at it's radial extremities than at its center when

Abstract: The process consists of starting from a lace or embroidery in cotton or synthetic fibers, applying to the model wax, resins or varnishes capable of increasing the size, then coating the model with gypsum and then introducing the coated model into a furnace. The heat destroys the model and leaves a cavity which has the shape of the model. The precious metal is introduced into the cavity in the molten form. Finally the article is allowed to solidify and the gypsum is crushed. The decorative article may be used for necklaces, bracelets or similar materials.

Abstract: A "lost foam" method of making a casting having a preform embedded at a selective location therein including the steps of: engulfing a porous preform in a fugitive pattern; embedding the pattern in a loose sand mold in a vessel; pouring molten metal into the mold cavity via a sprue and runner system formed in the sand bed so as to destroy the pattern and fill the mold cavity with metal; pressurizing the vessel to force molten metal from the cavity into the porous preform; replacing metal lost from the cavity with make-up metal from the sprue and runner system; allowing the casting to solidify; and removing the casting from the sand bed.

Abstract: An orthopaedic implant comprising a cast metal base member having an outer surface and an ingrowth surface comprising a plurality of attachment spacer elements of unequal lengths integrally cast with said base member and a metal attachment element integrally cast with said spacer elements, said attachment element having connecting elements extending between said spacer elements to allow attachment of the bone to occur between an underside of said connecting elements and the outer surface of said base member. The invention also consists of a method for preparing such an implant, wherein the spacer elements are of equal or unequal length, which comprises inserting a preformed ceramic pattern for the ingrowth surface into a die for the implant, injecting a meltable material in its molten state into the die at a temperature below the melting temperature of the ceramic to fill the holes and grooves of the pattern.

Abstract: A method of producing polymeric foam patterns for use in evaporable foam casting. A positive three-dimensional model of the metal part to be cast is made by a layered prototyping process in which layers of sheet material are bonded in superimposed relation and the contour of the part to be cast is cut into each layer as it is applied to preceding layers to provide the model. A metal, such as copper, is then deposited on the working surface of the model to provide a rigid self-supporting shell having a surface which is the negative image of the part to be cast. The shell, after separation from the model, is then mounted in a die casting mold with the negative surface bordering a die cavity. Beads of a polymeric material, such as polystyrene, are introduced into the die cavity and heated to fuse the beads and provide a foam pattern which is identical in configuration to the metal part to be ultimately cast.

Abstract: A method of constructing a fully dense metal part or a metal mold half for mating with another mold half to form a mold for casting multiple parts. Steps include placing a pattern in a tubular mold base, casting a ceramic member onto critical surfaces of the pattern, removing the pattern from the mold base, covering the critical surfaces transferred to the ceramic member with a powdered metal having a melting temperature greater than that of an infiltration metal, placing a quantity of an infiltration metal over the powdered metal, placing the tubular mold base in a furnace at a temperature sufficient to melt the infiltration metal without melting the powdered metal, and removing the ceramic member from the first open end of the tubular mold base to expose the critical surfaces. The quantity of the infiltration metal is sufficient to fill voids between the particles of the powdered metal when the infiltration metal is melted, thereby generating a fully dense metal part.

Abstract: A method of making a ceramic shell mould for casting includes making a pattern having an internal cavity in two parts from a disposable material, glueing the two parts together to complete the hollow pattern, filling the internal cavity with a ceramic material, and simultaneously or subsequently forming a shell of a ceramic material around the filled pattern. The pattern can then be eliminated to obtain a casting mould with an inner core made in situ.

Abstract: A method of forming an open riser in a mold includes telescoping a heat consumable tapered plug into the upper end of a riser sleeve, which projects above the riser sleeve and cope sand level so as to be advanced into the riser sleeve during squeezing of the mold sand. The plug is vaporized or consumed by hot metal during casting, creating an open riser.

Abstract: Low carbon stainless steel parts are formed utilizing a high vacuum of 20" to 29" of mercury during the pouring stage of the lost foam process.

Abstract: The invention discloses an improved method for forming metal matrix composite castings. The method achieves the casting having increased mechanical properties by using a selectively permeable mold in conjunction with pressurized gas. This allows a greater degree of metal infiltration within the interstices of a suspended preform. The method teaches the use of whiskered, fibered and particulated ceramic constituents for use in the preform, as well as various embodiments of casting methods.

Abstract: A method for casting a housing and insert assembly including a housing and a cast-in-place insert. The casting method comprises the steps of providing a prefabricated insert, surrounding the insert with an evaporable foam pattern to form a pattern and insert assembly, and utilizing the pattern and insert assembly in a lost foam casting process wherein the pattern is replaced by a material to form the housing and insert assembly.

Abstract: A film-like molded body having a hollow portion of a predetermined contour and made from a disappearing material is formed first using a mold. Also, a disappearing model is prepared by dividing it into a plurality of disappearing model elements. Then, the disappearing model elements are placed so as to enclose the film-like molded body with the film-like molded body as a core and are bonded together and fixed using an adhesive. Accordingly, the disappearing model can be prepared easily while preventing the adhesive from being forced out into the disappearing model and dispensing with extraction of the film-like molded body.

Abstract: A method of manufacturing one-piece composite drill bits or coreheads suitable for drilling or coring petroleum wells or in mining. A shell (32) of hard wear-resistant and erosion-resistant material is formed by investment casting in a finished form requiring nominal or no finish shaping. A shank (44) of machinable material is then cast inside the shell, in conditions which cause fusion bonding of the two materials to form a one-piece composite drill bit (42) or corehead by the two-stage casting procedure. The shank (44) is finish machined to form a connection for attachment to a drill string. Pockets (20) for cutter inserts and gauge protectors can be pre-formed to final dimensions in the hard shell (32). The investment mold for the shell (24) allows the hard material to be cast in the required shape with little or no final shaping. The method enables drill bits and coreheads to be manufactured at relatively low cast by eliminating most or all skilled manual finishing operations.

Abstract: An improved high impact metal clubhead with a unique reinforced composite face wall, increased radius of gyration, and a positive lift air foil surface contour. The composite face wall includes an impact supporting wall rigidified by a pattern of integrally cast reinforcing bars that extend forwardly, rather than rearwardly, from the supporting wall. The reinforced supporting wall is covered by a very hard plastic ball striking insert that is cast in situ over the supporting wall. The increase in radius of gyration is accomplished by extending the heel and toe portions of the clubhead along the face wall further from the geometric center of the head, beyond present day parameters for high impact clubheads. And the positive lift is effected by contouring the top wall of the clubhead downwardly and rearwardly from the base wall more severely almost to the plane of the sole plate, and flattening the rear wall so it is almost co-planar with the sole plate.