Abstract: The apparatus for the production of directionally solidified castings (10) in a vacuum casting plant comprises a cooling attachment with members (60) between a flat cooling plate (6) and the mold shell (2), by means of which member zones of different orientation of the direction of solidification can be produced in the casting. This apparatus is particularly suitable for the production of components in the form of a wheel--e.g. turbine wheels in aircraft jet engines--in which a radial alignment of the texture structure is advantageous in order to increase strength.

Abstract: A technique of preparing graphite molds for growing single crystals of active metals and alloys. The inner surfaces of the graphite molds in contact with the growing up single crystals are of passive graphite. Various types of single crystal selectors are available in the graphite molds.

Abstract: A mold is used to cast an article as a single crystal having selected primary and secondary orientations. The mold includes an article mold having a configuration corresponding to the configuration of the article to be cast. A starter section contains a starter cavity in which one or more crystals form. A seed crystal is disposed in the starter cavity. A crystal selector has a passage which extends between an upper end of the starter and a lower end of the article mold. To promote the growth in the crystal selector passage of a crystal having primary and secondary orientations corresponding to the selected primary and secondary orientations of the article, the longitudinal central axis of the crystal selector passage is disposed in a single plane which is parallel to a plane containing the selected primary orientation axis of the single crystal article and the selected secondary orientation axis of the single crystal article.

Abstract: A mold structure includes an article mold having a mold cavity with a configuration corresponding to the configuration of the article to be cast. A starter section contains a starter cavity in which a plurality of crystals form. A crystal selector has a passage which extends between an upper end of the starter cavity and a lower end of the article mold cavity. To promote the growth in the crystal selector passage of a crystal having primary and secondary orientations corresponding to selected primary and secondary orientations of the article, the crystal selector passage has a portion which slopes downwardly in the direction of solidification of metal along the crystal selector passage. Without the use of a seed crystal, the cast article will have a secondary orientation axis which is almost always within plus or minus 30 degrees of a selected secondary orientation axis.

Abstract: The tapered core/shell lock includes notches which, in conjunction with protrusions from the shell mold, prevent axial slip of the core main body. In addition, the core/shell lock provides a tapered core print area which is much larger, and extends further into the shell mold, then the conventional "T" bar core/shell lock. By increasing the axial length of the core print area, shifting at the tip of the core main body is reduced, while tapering of the core print eliminates the need to lacquer slip the end of the core/shell lock, eliminating addtional sources of core shift.

Abstract: During the casting of reactive metals, the depletion of reactive elements from molten metal in an article mold cavity is prevented by blocking a feeder passage after filling an article mold cavity with the molten metal. To block the feeder passage, a valve member is floated on the molten metal. As the level of the molten metal rises, the valve member moves into sealing engagement with a valve seat. To make a mold structure containing the valve member, the valve member is positioned in a pattern of the mold structure. After covering the pattern with ceramic mold material, the pattern is removed to leave the valve member in the mold structure.

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.

Abstract: A reinforced ceramic investment casting shell mold and method of making such mold. The ceramic investment casting shell mold includes alternate, repeating layers of a ceramic material and a ceramic stucco defining an overall thickness of the shell mold. A fibrous reinforcing material is disposed in the alternate, repeating layers at an intermediate thickness of the shell mold. The fibrous reinforcing material has high tensile strength at elevated temperature and a coefficient of thermal expansion that is less than the coefficient of thermal expansion of the ceramic material and the ceramic stucco. The fibrous reinforcing material is preferably woven into a twisted yarn and disposed in a generally spiral configuration.

Abstract: A ceramic core molding composition, which includes alumina fibers, zircon, and fumed silica in an amorphous silica base, reduces shrinkage and shrinkage stresses during the core production process. Cores produced utilizing the disclosed composition and method exhibit an improved resistancce to macrocracking over conventionally produced cores.

Abstract: A shell mould comprising an inner layer of ceramic material which has a predetermined co-efficient of thermal expansion at a predetermined temperature and an outer ceramic layer of lower thermal co-efficient than the inner layer. The outer layer subjects the inner layer to compression on firing and during casting.

Abstract: Apparatus useful in forming a mold from a wax pattern in an investment casting process, the invention provides a loop element having arm elements which spiral downwardly from and inwardly of the loop element to a base element. Sprue pins mount wax patterns to the loop element in a casting process known as the "lost wax" technique, the apparatus of the invention being particularly useful in the environment of a dental laboratory for formation of crowns and the like of high density. The loop element and arm elements of the apparatus leave channels in the investment material on "burn out" which quickly accelerate a casting material, such as a metal alloy, into the formed mold or molds with a reduction of turbulence which results in fewer defective castings. The channel geometry provided by the apparatus provides benefits due to a lack of right angles or sharp corners which restrict the flow of casting material into the mold or molds.

Abstract: A ceramic shell mold and method of making the same. The ceramic shell mold includes a facecoat layer comprised of a first ceramic material. A plurality of alternating layers are formed overlaying the facecoat layer. The alternating layers are comprised of a second ceramic material and a third ceramic material, the third ceramic material having thermophysical properties different than the second ceramic material. The second ceramic material and the third ceramic material are preferably a zircon-based material and an alumina-based material, respectively. The resultant ceramic shell mold has a greater high temperature creep resistance than a shell mold formed solely from the second ceramic material or solely from the third ceramic material.

Abstract: A single crystal selector has a passage into which a plurality of crystals grow from a starter cavity and from which a single crystal emerges into an article mold cavity. The single crystal selector passage includes a linear lower vertical portion which extends upwardly away from an end portion on the starter cavity. A linear vertical upper portion of the selector passage extends downwardly from a lower end portion of the article mold cavity. A single bend portion of the selector passage extends between the upper and lower portions of the selector passage. A support element extends upwardly from a lower section of the selector to an upper section of the selector to at least partially support a single bend section of the selector. The single bend portion of the selector passage has a generally circular cross sectional configuration with a diameter which is less than 0.25 inches. The single bend portion of the selector passage extends sidewardly for a distance which is at least 1.

Abstract: A metallic golf club head formed with a one-piece thin-walled forward body including a ball striking face, a perimeter wall having a uniform rearward depth and a hosel, and a rear cover that encloses the perimeter wall.

Abstract: An aqueous bath or slurry for use in forming a shell mould, comprising from 20 to 40 wt. % of colloidal silica, from 20 to 40 wt. % of finely ground zircon, from 15 to 25 wt. % of silica sand, from 15 to 35 wt. % of finely ground fused silica, and from 1 to 5 wt. % of finely ground cristobalite. The shell-mould is made by repeatedly dipping a wax model into the bath or slurry to form a coating of the desired thickness, and then thermally treating the shell-mould so formed by placing the mould into an oven, heating the oven to a temperature between 1050.degree. C. and 1200.degree. C., maintaining the temperature for a period of between 1 and 2 hours, and then allowing the oven and mould to cool to ambient temperature. The mould obtained contains from 10 to 30 wt. % of cristobalite at ambient temperature.

Abstract: A cushioning sheet made of a flammable material for use, e.g. in denture casting. It is inserted into a casting frame and adapted to burn out when heated to leave a space between a casting frame and a casting mold in the frame. The space serves to absorb the difference in the thermal expansion between the frame and the mold, thus preventing the casting mold from cracking or breaking. The cushioning sheet is formed with apertures. The casting material penetrates through the apertures, abutting against the casting frame to support the casting mold upon the frame even after the cushioning sheet has burnt out.

Abstract: Method and apparatus for controlling radial solidification in cast turbine wheel or nozzle assembly so as to produce an equiaxed fine grain structure in a hub portion and a directionally solidified grain structure in an integral blade portion by means of adjustable heat shields and heating elements disposed above and below the mold.

Abstract: An improved mold includes an upper mold section having a primary distribution system which is connected with a furnace and a lower mold section which is withdrawn from the furnace on a chill plate. A baffle plate is supported from the primary distribution system. The lower mold section includes a secondary distribution system which is connected in fluid communication with the primary distribution system at separable joints. The secondary distribution system is connected in fluid communication with article molds which are disposed in an annular array. During pouring of molten metal, reaction forces are transmitted to the chill plate from the pour cup through a support post and baffle plate. Once the article molds have been filled with molten metal, the chill plate is lowered. The primary distribution system which is connected to the furnace, remains stationary.

Abstract: Apparatus for the shaping of metal in a bottom-gated mold by the vacuum-induced countergravity casting method including an upstanding levee on the periphery of the drag and circumscribing the chamber-to-mold joint and/or the cope-to-drag joint for isolating such joint(s) when the mold is immersed in an underlying melt.

Abstract: To form a turbine engine component, metal airfoils are positioned in an annular array. Outer end portions of the airfoils are embedded in a wax outer shroud ring pattern and inner end portions of the airfoils are embedded in a wax inner shroud ring pattern. A mold is formed by covering the metal airfoils and the shroud ring patterns with ceramic mold material. The wax of the shroud ring patterns is then removed from the mold to leave inner and outer shroud ring mold ring cavities. The shroud ring mold cavities are filled with molten metal which is solidified to form inner and outer shroud rings interconnecting the airfoils. To accommodate thermal expansion of the airfoils relative to the shroud rings, a slip joint is provided between at least one end portion of each of the airfoils and a shroud ring. To enable the slip joint to be formed, molten metal solidifies in the shroud ring to be formed, molten metal solidifies in the shroud ring cavities free of metallurgical bonds to the airfoils.

Abstract: Disclosed are a mold, apparatus and method for obtaining articles of controlled crystallographic orientation using solidification from seeds. The starter section of a directional solidification mold is adapted to both contain a seed and receive molten metal which is flowed over and about a seed to heat and partially melt it. A selector section of the mold has reduced cross section compared to the starter section so that only epitaxially solidified metal will be formed in the article section. A barrier layer resistive to molten metal is applied to portions of the seed to facilitate its removal and reuse.

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.

Abstract: Molding material composed of casting sand coated with a thermosetting resin and hydrous magnesium silicate clay mineral which may be impregnated with an acid and/or coated with a thermosetting resin, and a shell mold produced from the molding material. This material and mold minimize generation of smoke and irritating gases at the time of mold making and casting.

Abstract: In casting metals for dental prosthetic use, superior dental castings free from shrinkage cavities can be obtained by delaying the cooling and solidification of molten metal in mold members such as a sprue, runner and gate and, if necessary, a molten metal reservoir into which the molten metal is poured. Such delay in cooling and solidification can be achieved either by forming the sprue and the like from a heat resisting ceramic tubular body or by further forming a heat insulating layer on the outer periphery of the tubular body.

Abstract: An improved mold includes an upper mold section having a primary distribution system which is connected with a furnace and a lower mold section which is withdrawn from the furnace on a chill plate. A baffle plate is supported from the primary distribution system. The lower mold section includes a secondary distribution system which is connected in fluid communication with the primary distribution system at separable joints. The secondary distribution system is connected in fluid communication with article molds which are disposed in an annular array. During pouring of molten metal, reaction forces are transmitted to the chill plate from the pour cup through a support post and baffle plate. Once the article molds have been filled with molten metal, the chill plate is lowered. The primary distribution system which is connected to the furnace, remains stationary.

Abstract: An investment shell mold of a texture having a stucco material dispersed in mullite useful for grain-oriented casting of a Ni-base super alloy is produced by preparing a slurry having alumina powder or a mixture of alumina powder with at least one ceramic powder selected from among zircon powder, mullite powder, and spinel powder blended with a silicate binder such as silica sol, applying the slurry to the surface of an expendable pattern made typically of wax for the production of the mold, then applying thereon a stucco material, thereafter repetitively applying substantially equal slurry and stucco material alternately thereon until the applied layers assume a prescribed thickness, allowing the applied layers to solidify, then heating the hardened layers to a temperature exceeding 1,400.degree. C. thereby enabling SiO.sub.2 produced from the binder and the alumina powder in the slurry to react with each other and produce mullite.

Abstract: The mold body contains a cavity and at least one vent passage for venting gas from the cavity through the body. The vent passage has a portion of predetermined regular shape extending part-way through the cavity wall defining at one end an inlet portion opening into a portion of the cavity with a substantially greater resistance than the cavity to penetration therein of casting material. The vent passage further has an outlet portion formed by an irregular crack in the mold body extending from an inner end exposed to the inlet portion through the mold body, the crack having one of its transverse cross-section dimensions short enough to prevent leakage of casting material therethrough. The mold is made by forming a partially bonded ceramic material containing a casting cavity and incorporating in a wall of the cavity a vent pattern of a shape to mold the portion of predetermined regular shape of the vent passage.

Abstract: Apparatus for the countergravity, shell-mold casting process comprising a gas-permeable shell mold sealed in the mouth of a vacuum chamber and a hollow, expendable, gas-permeable, thermally degradable, core disposed with the molding cavity for engulfment and retention by the metal being cast. The core defines a central evacuation cavity and an unobstructed vent for exhausting the evacuation cavity into the vacuum chamber such that the pressure in the evacuation cavity is substantially equal to that in the vacuum chamber during casting.

Abstract: A thin-walled, resin-bonded sand, shell mold for the vacuum counter-gravity casting of metal comprising cope and drag halves glued together at a parting line therebetween. The drag includes a flange extending beyond the periphery of the cope which flange has an upper sealing surface formed by a drag-shaping pattern for effecting a seal with the mouth of the vacuum chamber used to fill the mold.

Abstract: The present invention provides a method for manufacturing a thin-walled ceramic casting mould which is particularly suitable for casting directionally solidified articles in which rapid cooling of the cast material is required. The mould is transfer moulded around a disposable pattern material and includes an integral core. The mould has an outer wall thickness of the order of 0.5 mm to 2.0 mm. The mould and core may be made of the same or different ceramic materials chosen for their strength or thermal conductivity. The method further provides for a series of high temperature disposable supports embedded in the disposable pattern material, providing support for the outer wall of the mould during the firing process. The disposable supports are disposed of at a temperature at which the mould has acquired self-supporting strength.

Abstract: A horizontal casting technique and mold for use specifically with shell molds and runner feeder sections. The runner feeder sections are assembled within the shell molds such that the ends of the runner feeder section protrude from the mold and can be flow connected to a runner feeder of an adjacent assembly. A plurality of these assemblies constitute the horizontal mold having a horizontal runner feeder and a plurality of shell molds in spaced, side-by-side relationship.

Abstract: A method and ceramic mold structure for use in producing articles having a predetermined crystalline orientation such as single crystals. The technique involves the use of a ceramic mold mounted on a chill plate with the mold defining a cavity tilted at an angle between about 5.degree. and 75.degree. relative to the vertical. One or more seed crystals are supported adjacent the chill plate and the orientation of the crystal is selected to provide a desired orientation in the resulting casting. The method results in improved solidification control, particularly with reference to avoiding defects caused by shrinkage.

Abstract: A method for moulding multiple castings in which each mould is fed from a source of molten metal through a thin slit the width of which lies in the range 1.25 mm down to 0.25 mm. The cast articles can easily be removed from the runner and riser system after casting without a machining operation so that the casting moulds can be packed closer together and more castings can be produced from each mould assembly. The thin slit also acts as a filter. A particular mould assembly seen in FIG. 2 is cylindrical and comprises a plurality of wedge-shaped mould segments 2 having mould cavities 4 in abutting faces. A central runner passage 6 is formed when the mould segments are assembled and the metal flows into the mould cavities through narrow slits 10 in one edge of each mould. After casting and removal of the mould the narrow flashing formed in the slits can easily be broken to remove the cast articles from the metal formed in the central runner passage.

Abstract: Casting metal in rigid, self supporting, gas permeable molds with one or more mold cavities for molding one or more parts, in which the mold cavities have gate passages with their lower open ends at the lower surface of the mold, by submerging the lower ends of the gate passages beneath the surface of molten metal and applying a reduced pressure to the upper surface of the mold to fill the mold cavities with molten metal to produce unconnected metal parts or groups of parts.

Abstract: A mold construction and method for use in producing articles having a predetermined crystalline orientation including single crystals. The technique employs a seed holder or cradle that is inserted into a bottom aperture of a ceramic mold to permit the precise orientation of one or more seeds relative to the article cavity and to provide improved solidification process control. The technique also facilitates pattern assembly and pattern removal operations during fabrication of the ceramic mold.

Abstract: In an investment casting method, a wax coating is provided to the exterior and interior surfaces of a thin-walled hollow metallic form. The wax coating on the exterior and interior surfaces is coated with a mold forming material. When the metallic form is heated, the wax will melt permitting removal of the form.

Abstract: The invention relates to a mould assembly including a plurality of individual moulds. The mould assembly of the present invention is made by separately transfer moulding a starter base 16, a plurality of moulds 12, a downpole 14 and pouring cup 19, providing each with mechanical locking features, such as screw threads, and joining them together into the assembly. Much greater flexibility is thereby achieved in materials and wall thicknesses, which can be different in different parts of the assembly to suit strength and heat transfer requirements, individual bits can be replaced, and the transfer moulding produces a compact homogeneous ceramic structure.

Abstract: An apparatus for casting doubly-oriented single crystal airfoils and similar articles includes a mold having an orientation selector which selects crystals having desired vertical and horizontal orientations. The orientation selector includes an upright primary growth passage having a lower end exposed to the upper side surface of a chill plate. A horizontal secondary growth passage is connected with the upper end of the primary growth passage and with the mold cavity. A gradient inducing passage is connected with the upper end of the primary growth passage and has a lower end exposed to the chill plate to promote the transmission of heat from the upper end of the primary growth passage to the chill plate after metal crystals have solidified in the gradient inducing growth passage.

Abstract: Insulating material is applied in selected mold surfaces and in critical thicknesses to prevent cracking of the mold and casting therein during the heating and cooling steps of high rate directional solidification processes.

Abstract: Directional solidification of a single crystal superalloy article may be accomplished using a mold with a starter section, and a selector section to convert columnar growth from the starter into single crystal growth. In such a process, the deviation of [001] crystallographic orientation with respect to the longitudinal axis of the article being formed is reduced from 9 degrees to 5 degrees by controlling the heat transfer in the starter section. A stepped starter section, wherein the lower subsection has a volume of 52-98% of the total starter volume, and wherein the upper subsection is relatively small in lateral dimension, has been found most useful. When the solidification interface moves into the smaller width upper subsection, it becomes more nearly planar, and results in improved columnar growth in the starter, and in reduction in the crystallographic deviation of the article.

Abstract: In a mould assembly for multiple castings each mould is fed from a source of molten metal through a thin slit the width of which lies in the range 1.25 mm to 0.25 mm. The cast articles can be easily removed from the runner and riser system after casting without a machining operation so that the casting moulds can be packed closer together and more castings can be produced from each mould assembly. The thin slit also acts as a filter. A particular mould assembly seen in FIG. 2 is cylindrical and comprises a plurality of wedge-shaped mould segments 2 having mould cavities 4 in abutting faces. A central runner passage 6 is formed when the mould segments are assembled and the metal flows into the mould cavities through narrow slits 10 in one edge of each mould. After casting and removal of the mould the narrow flashing formed in the slits can be easily broken to remove the cast articles from the metal formed in the central runner passage.

Abstract: A refractory mix comprising an acid stabilized aqueous zirconia sol and an active refractory material in an amount effective to gel said sol and articles prepared therefrom.

Abstract: A method and a support structure for use in casting metal articles which define at least one internal passage and wherein the support structure is associated with a core or cores employed during the casting operation. In that operation, the cores are confined within a disposable pattern, and a ceramic mold is formed around the pattern. When the pattern material is removed, a mold cavity is provided with the core positioned in the cavity to form the desired opening in the cast article. The support structure for the core comprises a member positioned between the core surface and the opposing mold surface. This member is encompassed by the pattern material when the pattern material is formed around the core. During the subsequent removal of the pattern material and also during curing of the ceramic mold, the support member serves to hold the core in place so that the dimension of the casting wall surrounding the internal passage can be precisely maintained.

Abstract: A method of epitaxially casting single crystal metal articles in molds, which comprises causing the solidification interface velocity vector to rotate through at least 90 degrees, preferably 180-540 degrees, about the axis of overall directional solidification growth. In addition, a mold section has a small passageway configured to prevent line of sight communication between the portion where the seed is contained and the article portion of the mold. Preferably, the passageway is shaped like a helix of 0.8-1.5 turns. A second seed can be formed in the mold of an article made from a first seed, and used to make a second casting. The invention reduces the normal increase in crystallographic variability which would otherwise be associated with such practice.

Abstract: A method and a mould for making a cast single crystal in which the casting mould comprises a main casting chamber and a seed crystal mounted at or adjacent the entry aperture to this chamber. The charge of molten metal is arranged to flow over the crystal to produce melting of its upper surface. The molten metal filling the mould is then arranged to solidify progressively from the seed crystal, which then imposes its own structure and orientation on the solidifying metal.

Abstract: A selector for use in allowing only one crystal from a directionally-solidified initiating mould cavity to grow into a main casting cavity is described. The selector comprises a ceramic member with a curvilinear groove formed in its surface. The selector is positioned in a two part ceramic shell mould which cooperates with the groove in the selector to form a curvilinear passage which selects the single crystal required.

Abstract: A ceramic shell mold for directional solidification of a single crystal metal article has an improved starter section which converts columnar grain growth to single crystal grain growth. The pitch or lead of the helix is chosen so that the separation between adjacent turns of the helix is less than twice the thickness of the layered ceramic shell material which comprises the mold. Thus, when the ceramic shell mold is formed by the repetitive application of layers of ceramic to a wax pattern, the gap between adjacent turns of the helix will be bridged when the mold has reached 50-80% of its final thickness. Then, continued accumulation of ceramic layers bridges the turns of the helix thereby giving it strength. A helical passage diameter in the 8-10 mm range significantly increases single crystal casting yields compared to smaller diameters commonly used heretofore.

Abstract: Disclosed is a core for producing halves of cambered hollow articles, such as bonded turbine blades. The core has opposing flanges which differ in thickness, since the opposing contour surfaces are rotated relative to one another, compared to the relationship of the contour surfaces in the interior of the hollow article being produced. Thus, the core is made thicker and more sound in the area of high camber where it is otherwise prone to be thin.

Abstract: Method and apparatus for producing ceramic shell molds characterized in that a plurality of pattern set-ups are arranged with their longitudinal axes transverse to an axis of rotation and are rotated as a group while applying fluent refractory material to produce either a multiple number of molds or a single mold. A ceramic shell mold characterized by a main sprue passage, a plurality of transverse sprue passages extending therefrom, and casting cavities gated into the transverse passages.

Abstract: A ceramic shell mold having the properties of being easily removed from the metal castings, high permeability, and a fired strength that can be controlled at levels lower than conventional molds, characterized in that the refractory used to make the mold is at least in part hydrated alumina.