Abstract: A method of casting or moulding an internally screw-threaded article comprises introducing casting or moulding material around two withdrawable flat core members which overlap within a mould cavity. The leading end face of each core member is formed with a male segment of the female screw thread to be formed in the article, the arrangement being that when the core members meet one another the two screw thead segments of the two core members are located to form two diametrally opposite segments of a male image of said female screw thread, withdrawing the core members from the mould cavity when the casting or moulding material has set and removing the cast article from the mould cavity.

Abstract: A method of removing refractory material from a component comprises contacting the refractory material with a chemically active agent whereby to convert the refractory material to a more easily removable substance, and removing the more easily removable substance. The method enables alumina cores defining cooling passages in cast blades for use in gas turbine engines to be removed at practically useful rates.

Abstract: A method and apparatus for the removal of mold core material from metal castings and for fragmentation of municipal waste material, e.g., paper products, involves heating and hydrating the materials within a pressure vessel. Chemicals active on the material to be processed or the hydration water are added during hydration to soften the material to be removed or fragmented. Excess liquid in the vessel is drained and pressurized steam is added for a selected period of time. A suitable temperature and pressure are achieved such that the moisture or liquid carried by the processed material will rapidly turn to steam or vapor when the pressure in the vessel is rapidly reduced by quickly opening an unloading means at the bottom of the pressure vessel. The sudden release of the pressure in the vessel causes the moisture to change to steam and a certain portion of the liquid in the material to flash to vapor in accordance with thermodynamic laws.

Abstract: A reinforced tubular core for casting gas turbine engine blades with cooling air passages therein is disclosed. A method of casting is also disclosed in which the blades are directionally solidified to produce columnar grained or single crystal blades and in which non-linear passages can be produced. The problem in producing such articles is that the moulds and cores used in the casting process are held at temperatures in excess of 1500.degree. for long periods and presently used silica cores deform during the process. Stronger cores of alumina or silicon nitride cannot be easily bent were believed to be non-leachable from the casting. The present invention provides a core having a tubular silica sheath with a solid alumina rod inside it for support. The sheath can be bent and the straight alumina rods can be inserted from opposite ends of the sheath.

Abstract: A method for electrohydroblasting of castings in a liquid medium with a view to removing core and molding sand, according to which castings are subjected to a series of electrohydraulic shocks and at the same time set in reciprocating motion. The reciprocating frequency of the castings and the length of their stroke are sufficient to produce a flow of liquid in the internal channels of the castings and thus remove core and molding sand therefrom. The method is carried out with the aid of an apparatus which comprises a casting-reciprocating mechanism interacting with an electrode-positioning mechanism so that the movement of the castings is synchronized with that of the electrode.

Abstract: A refractory mould core for producing metallic castings of complicated internal shape formed from a water-soluble salt having the following particle size distribution:100% by weight of the particles have a size less than 750 .mu.m;90% by weight of the particles have a size of 8-600 .mu.m;80% by weight of the particles have a size of 5.5-500 .mu.m;70% by weight of the particles have a size of 4-400 .mu.m;60% by weight of the particles have a size of 2.8-350 .mu.m;50% by weight of the particles have a size of 2.0-280 .mu.m;40% by weight of the particles have a size of 1.6-220 .mu.m;30% by weight of the particles have a size of 1.0-180 .mu.m;20% by weight of the particles have a size of 0.3-160 .mu.m;10% by weight of the particles have a size of 0.1-125 .mu.m.

Abstract: A process for fabricating miniature hollow gold spheres comprising the steps of gold plating copper plated miniature balls having centers employing compressible material, piercing small holes in the balls, extracting the compressible materials from the balls along with the cutouts formed by piercing step, and heat treating said hollow gold spheres.

Abstract: A method of making a die cast aluminum based engine block with a closed deck is disclosed. A core assembly having at least one water soluble alkaline metal salt core member is stationed on a bore die of a die casting assembly for the block. The core assembly also preferably comprises an iron cylindrical liner centered within the salt core member by an aluminum mesh collar which dissolves in the cast metal during high pressure aluminum die casting. The salt core member is fabricated by die casting under pressure and heat to form a shaped body which, as a core, cooperated to define a substantially closed chamber to serve as the water jacket for the block. The salt core member is removed from the cast block by water dissolution admitted through small port openings in the closed deck block to form a brine, which brine is then washed out of such port openings.

Abstract: For removing and dissolving sand mold residues from cast parts, particularly sand mold residues containing zirconium oxide and titanium oxide, there have previously been used mechanical and electrochemical processes in salt melts. However, these processes are very expensive, attack the surface of the cast pieces or fail to work with sand mold constituents which are difficult to dissolve. These disadvantages are avoided by inserting the cast parts having adhering sand mold residues into a melt of 55 to 97 weight % of alkali metal hydroxide and 3 to 45 weight % of one or more fluorides of an element of the first to third main group of the periodic system of elements and/or zinc at 400.degree. to 900.degree. C. Preferably the salt melt additionally contains a boron-oxygen and/or a boron-fluorine compound.

Abstract: A water soluble core comprises a mold product prepared by a mixture of sand, potassium carbonate as a first binder and at least one of barium carbonate and alkali silicate as a second binder. This water soluble core is utilized for a method of manufacturing a cast rotor for forming ventilation ducts of an induction motor.

Abstract: A cantilever for a pickup cartridge comprising a base in the form of a solid rod or a pipe coated with a layer of a substance exhibiting a high modulus of elasticity ratio higher than 5000 Kg/mm.sup.2. The substance is for example boron or a boride.

Abstract: A method for the manufacture of an aluminum alloy casting comprises pouring a molten aluminum alloy into a mold having a sand core therein, removing a portion of the sands used to form the core from the casting after the solidification thereof, heating the casting and, simultaneously, removing the remaining portion of the sands from the casting, and machining the casting to complete an aluminum alloy article having an aperture or cavity or any other trace complemental to the core.

Abstract: A method of casting a blade or vane for a gas turbine engine which enables the production of more complex internal shapes than those which may be made by prior art methods. The method of the invention includes the steps of:making a temporary filler piece from a disposable material,holding the filler piece in place in a die,injecting the core material into the die and causing it to solidify round the filler piece,removing the core from the die,causing the filler to be removed from the core to leave within the core a cavity having the shape of the filler, andusing the core thus produced in an investment casting process to form the blade or vane shape.

Abstract: An explosion treatment apparatus useful for confined shock exposure of materials as for removal of sand cores from finished castings and, in particular, cores in permanent mold castings in which a horizontally axised index device successively presents plural and substantially similar cavities to a position at which sealing, evacuating, fueling and ignition occur. This results in an explosion which occurs upon closure of each chamber. After the confined explosion, the cavity is opened and all cavities are indexed so that the fired cavity can be unloaded, the previously unloaded cavity can be dumped, the next adjacent cavity can be reloaded, and the reloaded cavity is presented to closure.

Abstract: Thermally collapsible core of three to five solid carbonaceous segments of generally equal volume and of wedge-like shape arranged around a collapse axis of the core in narrowly spaced apart relation to each other. Core includes spacers occupying a minor portion of the narrow spacing nearest the external periphery of the core and which are made of metal, glass, ceramic or mixtures thereof having a melting point below the highest temperature to which the core is subjected by molten material solidifying therearound, e.g. fusion-cast refractory. The segments are the larger parts of the core. Heat transferred from solidified molten material to core causes spacers to melt and allow segments to collapse inwardly toward collapse axis to accommodate cooling shrinkage of casting without cracking. Melted spacers can drain downwardly out of core. Design yields highly quenched microstructure in fusion-cast refractory, which is especially beneficial in tap hole blocks for steelmaking furnaces and vessels.

Abstract: A casting core for the creation of difficultly accessible cavities in castings of aluminum or of one of its alloys, produced from a water-soluble salt as base substance and burnt sugar as binding agent, and a process for the production of such a casting core wherein the base substance is mixed with burnt sugar in aqueous or organic solution, pressed in molds, and baked at elevated temperature.

Abstract: A process for producing a hollow cast product in which a hollow flexible mandrel is placed into the crucible of a mold with one end of the mandrel extending out of the mold, molten metal is introduced into the mold crucible and left to solidify in the crucible and the mandrel is removed from the mold to thereby form a hollow cast product having a bore which has the smooth or concavo-convex peripheral surface and is straight, bent or meandering.

Abstract: The material used for the production of cores for precision molds is a metal which is oxidizable at relatively low temperatures, i.e., below the solidification temperature of the melts for pouring, and which passes directly from the solid state to the gas state by oxide sublimation. This greatly speeds up the dissolving of cores, particularly small diameter cores, out of the castings.

Abstract: Ceramic cores suitable for use in investment casting operations are molded from a mixture containing comminuted refractory which includes partially dehydrated gypsum and a sublimable binder. When the sublimable binder has been sublimated from the molded core, it is soaked in water in order to hydrate the gypsum and cause it to set.

Abstract: Mold core for electrically melting metals for casting hollow ingots wherein the core wall is divided lengthwise on its periphery and is designed to be taken apart. The wall is preferably made of at least two partial cylinders between which stave-like keys are positioned which can be removed inwardly.

Abstract: A method for simultaneously forming an integral porous outer barrier layer having a density gradient therein on selected external surfaces of a fired ceramic article and for increasing the porosity content and crushability characteristics thereof embodies the firing of a ceramic compact comprising a reactant fugitive filler material and a ceramic material in a controlled atmosphere.

Abstract: A reactant fugitive filler material is employed in a material composition which includes alumina-based ceramics of one or more particle sizes. The reactant fugitive material provides sufficient reactant material at an elevated temperature to form a fired ceramic article which has a porous microstructure in which the grain morphology is characteristic of grains which have undergone vapor phase transport action.

Abstract: A method for increasing the porosity and crushability characteristics thereof embodies the firing of a ceramic compact comprising a reactant fugitive filler material and a ceramic material in a controlled atmosphere.

Abstract: A method for simultaneously forming an integral barrier layer on selected external surfaces of a fired ceramic article and for increasing the porosity content and crushability characterstics thereof embodies the firing of a ceramic compact comprising a reactant fugitive filler material and a ceramic material in a controlled atmosphere.

Abstract: A method for simultaneously forming an integral barrier layer on selected external surfaces of a fired alumina-based compound ceramic article and for increasing the porosity and crushability characteristics thereof embodies the sintering of a ceramic compact comprising a reactant fugitive filler material and the alumina-based compound ceramic material in a controlled atmosphere.

Abstract: A fired alumina article having a core of material having from 20 to 65 percent continuous porosity by volume and desired crushability characteristics and an integral outer barrier layer consisting of porous alumina having a density gradient.

Abstract: A core for investment casting directionally solidified eutectic and superalloy material consists of alumina which has a porous microstructure in which the grain morphology is characteristic of grains which have undergone vapor phase transport action.

Abstract: Cores made of either Y.sub.2 O.sub.3, Y.sub.3 Al.sub.5 O.sub.12, LaAlO.sub.3, MgAl.sub.2 O.sub.4 or Al.sub.2 O.sub.3 are removed from castings of advanced superalloy materials by immersion in a molten salt bath of either Li.sub.3 AlF.sub.6 or a mixture of CaF.sub.2 -NaF.

Abstract: Cores made of alumina-based ceramics, such as .beta.-alumina materials, are substantially non-reactive with directionally solidified eutectic and superalloy materials, do not cause hot cracking of the same, and are easily leachable from the cast metal.

Abstract: A method for manufacturing a thermally highly stressed, cooled component, more particularly, a blade for turbine engines. A component of the above-mentioned type has a central supporting core formed of a solid material and has connected thereto several short, radially outwardly projecting ridges which, in turn, carry an outer shroud concentrically encompassing the supporting core, and which is made of a through-porous material, whereby the supporting core, ribs, and outer shroud are cast in a single piece.

Abstract: A heat insulation layer is provided on the exterior surface of a port liner. The port liner is installed in the exhaust port passage upon casting of a cylinder head by filling a moulding material in the cavity of the port liner to serve as an exhaust port, mounting preformed and cured separate layers of moulding material on the exterior surface of the port liner and using the port liner with a mass of a moulding material therein and separate layers of a moulding material thereon as a core for casting an exhaust port passage and a heat insulation layer of the exhaust port.

Abstract: Caustic solutions are employed in an autoclave process to rapidly remove cores made of .beta.-Al.sub.2 O.sub.3 from directionally solidified eutectic alloy and superalloy materials.

Abstract: Caustic solutions are employed in an autoclave process to rapidly remove the cores made of Y.sub.2 O.sub.3 from directionally solidified eutectic alloy and superalloy materials.

Abstract: This invention relates to the making of negatives intended for the production of bodies which contain cavities of predetermined shapes.The term "negative" signifies a disposable core member, for example as used in some molding techniques such as the lost wax process. The negative at least partly matches the cavities which latter form two independent systems of regularly distributed intersecting channels with the channels in any one same system intercommunicating via ducts which are themselves regularly distributed.

Abstract: A method of producing cast articles having internal cavities is disclosed. The method is particularly suitable for casting gas turbine components from nickel base and cobalt base superalloys. The method comprises: forming a core to the desired cavity configuration, the core consisting essentially of densified silicon nitride; securing the core within a mold; casting the alloy within the mold and around the core; removing the solidified cast article from the mold; and leaching the silicon nitride core from the casting in molten sodium hydroxide.

Abstract: A weakly acid solution of either NH.sub.4 NO.sub.3, NH.sub.4 Cl, NH.sub.4 HSO.sub.4, CH.sub.3 COOH or equimolar CH.sub.3 COOH -- CH.sub.3 COONa is employed to remove cores of either Y.sub.2 O.sub.3 or Sm.sub.2 O.sub.3 from castings of advanced superalloy materials. A molten salt bath may be used thereafter to remove reaction products formed by the reaction of the materials of the core and the metal casting.

Abstract: An alumina core for investment casting directionally solidified eutectic and superalloy materials consists of a central portion which has porosity which is continuous throughout. The material of the central portion has a micro-structure which is characteristic of alumina grains which have undergone vapor phase transport action. An outer layer of alumina encompasses the central portion and in integral therewith and contains porosity which is discontinuous.

Abstract: Composition for production of cores and casting molds comprises 100 parts by weight of grain base, particularly quartz sand, 0.5 - 30 parts of alkal metal hydroxides, 1 - 40 parts of alkali metal carbonates, 1 - 15 parts of water as well as 0.2 - 10 of known hydrophilic binders. The composition according to the invention is removed from the cast or mold by subjecting the core in the cast or mold to the action of solvent, particularly water, preferably by dipping.

Abstract: Alumina doped with from 1 mole percent up to about 20 mole percent magnesia is suitable for use as a core material for casting and directional solidification of advanced super-alloys. The core material is leachable in KOH and NaOH in an autoclave at an elevated temperature and elevated pressure.

Abstract: A ceramic suitable for use in the casting of advanced superalloy materials has a structure including a predetermined porosity content and a material microstructure characterized by a high density of microcracks.

Abstract: A ceramic article suitable for use in the casting of advanced superalloy materials has a structure of a predetermined porosity content and consists of either 3Y.sub.2 O.sub.3 .multidot. 5Al.sub.2 O.sub.3, Y.sub.2 O.sub.3 .multidot. Al.sub.2 O.sub.3 or 2Y.sub.2 O.sub.3 .multidot. Al.sub.2 O.sub.3 or two-phase mixtures of these single-phase materials.

Abstract: This invention relates to the making of negatives intended for the production of bodies which contain cavities of predetermined shapes.The term "negative" signifies a disposable core member, for example as used in some molding techniques such as the lost wax process. The negative at least partly matches the cavities which latter form two independent systems of regularly distributed intersecting channels with the channels in any one same system intercommunicating via ducts which are themselves regularly distributed.

Abstract: The crushability of a ceramic article suitable for use in the casting and directional solidification of advanced superalloy materials is enhanced by utilizing a two-phase mixture of material and inducing microcracks in the material. The crushability is further enhanced by forming the article to include a predetermined porosity content.

Abstract: Cores made of either Y.sub.2 O.sub.3, Y.sub.3 Al.sub.5 O.sub.12, LaAlO.sub.3, MgAl.sub.2 O.sub.4 or Al.sub.2 O.sub.3 are removed from castings of advanced superalloy materials by immersion in a molten salt bath of either Li.sub.3 AlF.sub.6 or a mixture of CaF.sub.2 -- NaF.

Abstract: Ceramic mold and core materials of magnesia doped alumina are removed from castings by a solution of either KOH or NaOH at elevated temperatures and pressures in an autoclave.

Abstract: In the casting of metal alloys to form hollow articles, a mold of a desired shape containing a core material fabricated to a desired configuration from a silicon yttrium or silicon lanthanide oxynitride is filled with a molten metal alloy while maintaining the mold under a vacuum or under a blanket of an inert gas after which the mold is allowed to cool slowly to room temperature. The casted metal alloy with the core material exposed at one end is removed from the mold and heated under ambient conditions, thereby causing the silicon yttrium or silicon lanthanide oxynitride to oxidize with a large volume expansion and a concomitant catastrophic failure of the core material. The broken pieces of core material are removed from the casting which has a smooth inner surface, an indication that no chemical reactions have occurred between the alloy and the core material.

Abstract: In a method for casting metal alloys, a molten metal alloy is introduced into a mold of a desired configuration containing a core material fabricated to a desired shape from titanium nitride while maintaining the mold under a vacuum. After allowing the mold to cool slowly to room temperature, the casted metal alloy with the core material exposed at one end is removed from the mold and immersed in a boiling caustic solution, thereby causing the titanium nitride core material to decompose. The casting so obtained has a smooth inner surface, an indication that no chemical reactions have occurred between the alloy and the core material.

Abstract: A band-shaped metal layer useful as a resistance layer and/or a contact layer is pyrolytically deposited onto a cylindrical substrate by surrounding the surface of the substrate with a mixture of a thermally decomposable metal compound and a carrier therefor and substantially simultaneously heating only precise surface areas of the substrate, as by a laser beam, to a temperature slightly above the thermal decomposition temperature of the metal compound and moving the substrate in a rotational and/or axial manner so that a band-shaped metal layer forms only at the heated surface areas of the substrate.

Abstract: A method of making aluminum castings having a self-fused high silicon content in the interior matrix near and at the surface. A sand core is coated with a tacky, low-ash, low-volatile adhesive along a predetermined zone. Silicon dust particles are deposited on said adhesive in bonded relation. Molten aluminum is cast into a mold cavity containing the coated core. After mold stripping, the silicon particles are exposed as metallurgically bonded to the aluminum but along an ultra-thin depth. At least some of the exposed silicon particles are machined to expose a planar facet and thereby increase the projected exposure of the silicon particles along the machined plane. The resulting product has a reduced shrinkage characteristic (typical of aluminum alloys having a high proportional precipitated silicon).

Abstract: The installation comprises a liquid container and an electrode holder located above said container and mounted with a provision for moving the electrode to the preset position relative to the casting. The container shell is made of two telescopically jointed parts with a pneumatic seal on the joint. Secured rigidly at the level of the upper face of the lower part of the shell is a casting support. A special mechanism delivers the casting onto the support and removes it therefrom. The casting is placed on the support with the upper part of the shell lowered which allows the positioning of the electrodes above the casting to be controlled visually. Then the movable part of the shell is raised, filled with water so as to cover the casting completely, and the cores are knocked out.