The buoyancy transfer jig includes: a rod-shaped rod portion which is disposed extending from an outside of a pattern to an inside of a hollow portion by way of an opening portion which is formed in a foamed mold and makes the outside of the pattern and the hollow portion connected with each other, and is disposed in self hardening sand filled in the hollow portion and the opening portion; and a plate-shaped blade portion which is formed continuously with the rod portion and is disposed in the casting sand.

The buoyancy transfer jig includes: a rod-shaped rod portion which is disposed extending from an outside of a pattern to an inside of a hollow portion by way of an opening portion which is formed in a foamed mold and makes the outside of the pattern and the hollow portion connected with each other, and is disposed in self hardening sand filled in the hollow portion and the opening portion; and a plate-shaped blade portion which is formed continuously with the rod portion and is disposed in the casting sand.

A method of providing datum features on a ceramic article including the steps of providing a ceramic member having a plurality of substantially parallel holes extending into the ceramic member. Providing a plurality of tubular mounts, the cross-sectional area of each tubular mount being less than the cross-sectional area of the corresponding hole. Applying adhesive to the exterior surface of each one of the tubular mounts and inserting an adhesive covered tubular mount into each one of the holes. Providing a fixture member having a plurality of substantially parallel projections extending from predetermined positions. Positioning the ceramic member on the fixture member such that each projection locates in one of the tubular mounts and fixes the tubular mounts at the predetermined positions. The ceramic article may be removed from the fixture member or located in a machine tool using the fixture member and machining the ceramic article.

A furnace assembly for dewaxing investment casting molds includes a housing having a top and a bottom and sides and extends along an axis to define a cavity. A plurality of tiles are supported in a spaced relationship with the bottom of the housing and define a pair of lower chambers for directing the wax vapors out of the cavity. A plurality of trays having apertures are supported by the tiles for moving molds through the housing. Chimneys connect to the lower chambers and a passageway is defined by the tiles for evacuating the wax and wax vapors from the cavity to the lower chambers and out through the chimneys. A pair of lower burners extends into the lower chambers for igniting wax vapors in said lower chambers. The heat from the lower chambers radiantly heats up portions of the furnace assembly that are disposed above the lower chambers.

An opening is provided in a foam pattern, and a coating agent is applied to the opening. The coating agent applied to the opening is taken as a beam having a sectional secondary moment I, a vertical plate thickness h, and a length L. It is assumed that a volume of a cavity part in the foam pattern is V (mm.sup.3), a bulk density of the casting sand filling the cavity part is ρs (kg/mm.sup.3), a density of the melt is ρm (kg/mm.sup.3), an angle of the opening with respect to a vertical direction is θ, and a transverse strength of the coating agent at the highest temperature during pouring of the melt is σb (MPa). A sectional shape of the opening, the angle θ of the opening, and the transverse strength σb of the coating agent are selected to satisfy the expression:

σbI>V(ρm−ρs){(hL/2)sin θ−cos θ}.

In the following expression, it is assumed that a thickness of a coating agent applied to a foam pattern [2] is t (mm), a diameter of a hole part [3] is D (mm), and a normal-temperature transverse strength of the dried coating agent is σc (MPa). At the time of producing a casting provided with a hole having a diameter of 18 mm or smaller and a length of 1 (mm), a coating agent that satisfies the following expression is used when a solidification end time te (sec) at which solidification of a melt ends on a periphery of the hole part [3] is within a time t0 (sec) at which thermal decomposition of the coating agent ends.

σc≧{t0/(t0−te)}×(1.5×10.sup.−4×1.sup.2/t.sup.2+160/D.sup.2)

A mold assembly for use in forming a component having an outer wall of a predetermined thickness includes a mold and a jacketed core. The jacketed core includes a jacket that includes a first jacket outer wall coupled against an interior wall of the mold, a second jacket outer wall positioned interiorly from the first jacket outer wall, and at least one jacketed cavity defined therebetween. The at least one jacketed cavity is configured to receive a molten component material therein. The jacketed core also includes a core positioned interiorly from the second jacket outer wall. The core includes a perimeter coupled against the second jacket outer wall. The jacket separates the perimeter from the interior wall by the predetermined thickness, such that the outer wall is formable between the perimeter and the interior wall.

A mold assembly for use in forming a component having an outer wall of a predetermined thickness is provided. The mold assembly includes a mold that includes an interior wall that defines a mold cavity within the mold. The mold assembly also includes a jacketed core positioned with respect to the mold. The jacketed core includes a jacket that includes an outer wall. The jacketed core also includes a core positioned interiorly of the jacket outer wall. The jacket separates a perimeter of the core from the mold interior wall by the predetermined thickness, such that the outer wall is formable between the perimeter and the interior wall.

The disclosure relates generally to mold compositions and methods of molding and the articles so molded. More specifically, the disclosure relates to mold compositions, intrinsic facecoat compositions, and methods for casting titanium-containing articles, and the titanium-containing articles so molded.

The disclosure relates generally to mold compositions and methods of molding and the articles so molded. More specifically, the disclosure relates to mold compositions, intrinsic facecoat compositions, and methods for casting titanium-containing articles, and the titanium-containing articles so molded.