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: An expendable and machinable pattern material capable of being cast in large blocks without shrinkage and machined to a casting shape useful in the lost pattern process of investment casting, the material consisting essentially of ethylene-vinyl resin, fatty acid ketone, and fatty acid.

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: 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: Reactive metals, such as titanium or nickel-chrome superalloys containing rare earths, are cast with mold and/or core surface areas formed from an improved slurry. The improved slurry contains yttria to form an inert surface which is exposed to the molten reactive metal. In order to prevent premature gelation of the slurry, the forming of defects in the mold and/or core surface areas, and the forming of defects in the cast article, the slurry contains a source of hydroxyl ions. The source of hydroxyl ions is sufficient to result in the slurry having a pH of at least 10.2 six days after initially mixing the slurry. The source of hydroxyl ions may be a metal alkali or an organic hydroxide. It is believed that the source of hydroxyl ions functions as a hydration suppressant for the yttria to prevent premature gelation of the slurry. The slurry contains a silicon oxide (SiO.sub.2) to alkali ratio which is equivalent to a silicon oxide to sodium oxide (Na.sub.

Abstract: Reactive metals, such as titanium or nickel-chrome superalloys containing rare earths, are cast with mold and/or core surface areas formed from an improved slurry. The improved slurry contains yttria to form an inert surface which is exposed to the molten reactive metal. In order to prevent premature gelation of the slurry, the forming of defects in the mold and/or core surface areas, and the forming of defects in the cast article, the slurry contains a source of hydroxyl ions. The source of hydroxyl ions is sufficient to result in the slurry having a pH of at least 10.2 six days after initially mixing the slurry. The source of hydroxyl ions may be a metal alkali or an organic hydroxide. It is believed that the source of hydroxyl ions functions as a hydration suppressant for the yttria to prevent premature gelation of the slurry. The slurry contains a silicon oxide (SiO.sub.2) to alkali ratio which is equivalent to a silicon oxide to sodium oxide (Na.sub.

Abstract: An improved mold has a coating of material having a relatively high emissivity. The surface of the coating has an emissivity which is at least twice as great as the emissivity of the surface of the ceramic mold material. When the mold is removed from a furnace chamber, the surface of the coating radiates heat at a relatively high rate. In one embodiment of the invention, the coating is applied to only a portion of the surface of a ceramic mold. In another embodiment of the invention, the coating of material having a relatively high emissivity is applied to only a portion of a crystal selector on a mold for a single crystal article. The relatively high rate of radiation of heat from the coated portion of the crystal selector increases the rate of growth of an adjacent single crystal grain. If desired, the entire mold can be covered with the coating of material having a relatively high emissivity. The coating of material having a high emissivity may be formed of graphite.

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: 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.

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: A method of producing cast metal tooling, especially injection molds or dies, characterized by the steps of making a thin walled, investment cast shell which defines the functional cavity surface of the tooling, and casting a suitable backing metal against the shell to form a composite die or mold structure.

Abstract: A pattern assembly for use in the lost pattern process of investment casting characterized by a center tree or sprue member including a central stem and a plurality of laterally projecting collars spaced apart along the stem and united therewith to provide the surface area for gating the patterns, the cross-sectional size of the stem being greater than the projecting width of the collar, whereby the stem serves to form a riser.

Abstract: For use in making investment molds by the lost pattern process, a pattern material which is machinable and has the capability of being melted out of the molds without cracking them, the material consisting basically of an ethylene-vinyl resin and at least one fatty acid ketone.

Abstract: A method of making investment shell molds by the lost pattern process characterized in that a strand such as wire or the like is wound circumferentially about a pattern assembly in at least one location before it is coated with refractory material to form a mold shell. Thereafter, the strand is unwound to separate the shell into segments, each of which is usable as a mold.

Abstract: A pattern set-up especially useful for making prosthetic dental appliances is assembled by attaching a plurality of refractory casts to a support member so that adjacent casts along the length of the support member are circumferentially offset with respect to one another. The casts carry expendable patterns that are connected to the support member by gating systems laid down on faces of the casts. The support member has outward protrusions supporting the weight of the casts and may be formed by a plurality of segments fitted together in end-to-end relation.