A core element of an investment core for use in a casting process used to produce an airfoil includes an investment core body, an extension connected to and protruding from the investment core body, and a connection portion connected to the investment core body and to the extension. The investment core body includes a ceramic material. A shape of the extension includes a tube with a centerline axis passing through a center of the extension. A shape of a cross-section of the extension taken along a plane perpendicular to the extension centerline axis includes an ellipse. The extension is connected to the investment core body by the connection portion.

A method for manufacturing a blade, the method includes casting a nickel alloy blade precursor having an airfoil and a root. The airfoil and the root are solution heat treating differently from each other. After the solution heat treating, the root is wrought processed. After the wrought processing, an exterior of the root is machined.

A core is provided for fabricating a blade to include an airfoil. The airfoil includes pressure and suction surfaces, leading and trailing edges extending along the pressure and suction surfaces and a tip shelf with a first sweep configuration and a wall. The core includes channel sections configured to form internal channels within the airfoil by casting processes and tip rods extending from respective portions of the channel sections proximate to a tip shelf location. The respective portions of the channel sections have a second sweep configuration corresponding to the first sweep configuration. The tip rods are configured to extend through the wall at an angle of about 5-12 degrees inclusive relative to a normal angle of the wall during the casting processes to form through-holes angled at about 5-12 degrees inclusive in the wall.

A hollow turbine airfoil or a hollow turbine casting including a cooling passage partition. The cooling passage partition is formed from a single crystal grain structure nickel based super alloy, a cobalt based super alloy, a nickel-aluminum based alloy, or a coated refractory metal.

Partial integrated core-shell investment casting molds that can be assembled into complete molds are provided herein. Each section of the partial mold may contain both a portion of a core and portion of a shell. Each section can then be assembled into a mold for casting of a metal part. The partial integrated core-shell investment casting molds and the complete molds may be provided with filament structures corresponding to cooling hole patterns on the surface of the turbine blade or the stator vane, which provides a leaching pathway for the core portion after metal casting. Core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold are also provided herein.

A method is provided for casting a component. Accordingly, a casting core is provided within a cavity of a component mold. The casting core defines an inner component shape and includes a core wall. The core wall defines a core outer surface and a core inner surface disposed opposite the core outer surface. The core inner surface defines a core cavity. The casting core also includes a removal facilitation feature. The component is cast within the cavity of the component mold with the casting core positioned therein. The cast component is removed from the component mold and the casting core is removed from the cast component.

A hollow turbine airfoil or a hollow turbine casting including a cooling passage partition. The cooling passage partition is formed from a single crystal grain structure nickel based super alloy, a cobalt based super alloy, a nickel-aluminum based alloy, or a coated refractory metal.

An airfoil core includes a first core portion that has a hybrid skin core, a tip flag core, and a trailing edge core. A second core portion has a serpentine core and a leading edge core.

A method of forming a coating includes providing a mold that has a flexible wall that defines a mold cavity, inserting a component that is to be coated into the mold cavity, the component having a component surface roughness and there being a coating gap defined between the component and the flexible wall of the mold cavity, introducing a molding slurry into the mold cavity, the molding slurry filling the coating gap and contacting the component so as to overcoat the component surface roughness, solidifying the molding slurry to form a green coating on the component, and consolidating the green coating to form a final coating on the component, the final coating having a coating surface roughness that is less than the component surface roughness.

A hollow turbomachine turbine blade including rising cavities communicating with a squealer tip of the blade through standard dust removal holes intended to remove dust and through inclined cooling bores intended to cool a barrier of the squealer tip by leading to a pressure side face of the blade, at least one rising cavity including a tip with no dust removal hole and an inclined cooling bore formed in its lateral wall and intended to cool the squealer tip barrier is enlarged to have a diameter at least equal to the standard diameter of a dust removal hole and thus also serve as a dust removal hole, so that the air flow extracted for cooling the blade is reduced, at least one of the cavities positioned facing the tip of one of the rising cavities having an increased volume corresponding to at least a volume deducted from the tip of the rising cavity.