A core tie having a varying cross sectional diameter, a component including such a core tie, and a method of casting a hot gas path component for a turbomachine are provided herein. In an embodiment, the core tie includes a tie member having an axial length; and a cross sectional diameter which varies along the axial length of the tie member. A variation in the cross sectional diameter of the tie member positively secures a position of the core tie relative to the core.

A core tie having a varying cross sectional diameter, a component including such a core tie, and a method of casting a hot gas path component for a turbomachine are provided herein. In an embodiment, the core tie includes a tie member having an axial length; and a cross sectional diameter which varies along the axial length of the tie member. A variation in the cross sectional diameter of the tie member positively secures a position of the core tie relative to the core.

A method of forming a component having an internal passage defined therein includes positioning a jacketed core with respect to a mold. The jacketed core includes a hollow structure formed from at least a first material and a second material, and an inner core disposed within the hollow structure. The method also includes introducing a component material in a molten state into a cavity of the mold, and cooling the component material in the cavity to form the component. The inner core defines the internal passage within the component.

A method of forming a component having an internal passage defined therein includes positioning a jacketed core with respect to a mold. The jacketed core includes a hollow structure that includes an interior portion shaped to define at least one interior passage feature of the internal passage. The jacketed core also includes an inner core disposed within the hollow structure and complementarily shaped by the interior portion of the hollow structure. The method also includes introducing a component material in a molten state into a cavity of the mold to form the component, such that the inner core defines the internal passage including the at least one interior passage feature defined therein.

A core for a turbine airfoil casting according to an embodiment includes: a center plenum section; and a plurality of outer passage sections; wherein the center plenum section includes at least one boss extending outwardly from the center plenum to an outer profile of the core.

A casting core assembly comprising: a first ceramic piece including a projecting post; a second ceramic piece including a socket encircling the post; and a ceramic filler material between the post and the socket, wherein at least one of: in axial section at at least one location the post has: a lateral protrusion of at least 15 micrometers relative to a location proximal thereof; and in axial section at at least one location socket has: a lateral recess of at least 15 micrometers relative to a location outboard thereof.

A method of forming an airfoil (12), including: abutting end faces (72) of cantilevered film hole protrusions (64) extending from a ceramic core (50) against an inner surface (80) of a wax die (68) to hold the ceramic core in a fixed positional relationship with the wax die; casting an airfoil including a superalloy around the ceramic core; and machining film cooling holes (34) in the airfoil after the casting step to form an pattern of film cooling holes comprising the film cooling holes formed by the machining step and the cast film cooling holes (102) formed by the film hole protrusions during the casting step.

A process for producing a coupler and an improved coupler are provided. The process produces a coupler by constructing a mold that is a replica of the coupler and is constructed from a plurality of mold components that are selected and assembled to form a mold having the shape of the coupler. The mold components may include a front mold component section that forms the head of the coupler, a rear mold component section that forms the shank of the coupler, and, optionally one or more shelf components forming a shelf of the coupler. The front, rear and shank mold components may themselves be made from a plurality of mold components that are assembled together. The mold is formed from a consumable material, coating with a heat resistant material so that the assembled mold components are within a mold volume, and molten metal is added to the mold volume.

A process for producing a coupler and an improved coupler are provided. The process produces a coupler by constructing a mold that is a replica of the coupler and is constructed from a plurality of mold components that are selected and assembled to form a mold having the shape of the coupler. The mold components may include a front mold component section that forms the head of the coupler, a rear mold component section that forms the shank of the coupler, and, optionally one or more shelf components forming a shelf of the coupler. The front, rear and shank mold components may themselves be made from a plurality of mold components that are assembled together. The mold is formed from a consumable material, coating with a heat resistant material so that the assembled mold components are within a mold volume, and molten metal is added to the mold volume.

There is provided a method for manufacturing a turbocharger bearing housing which can prevent a collapsible core from being damaged when molten metal is cast in the mold. The method for manufacturing a bearing housing of a turbocharger is that the bearing housing of the turbocharger is formed with a cooling passage for circulating cooling liquid by casting using a collapsible core. The collapsible core includes the end part forming portions (a one end forming portion and an other end forming portion) corresponding to the end portions of the cooling passage and having a substantially elliptical cross-section, and a fixing portion holding the end part forming portions and being embedded in a mold and fixed to the mold.