In a method for removing a carbon-containing pattern material from a casting shell, a first step evaporates and pyrolizes the pattern material to leave carbon and a second step oxidizes the carbon.

The present disclosure relates to a method of forming a cast component and a method of forming a casting mold. The method is performed by connecting at least one wax gate component to a ceramic core-shell mold. The ceramic core-shell mold includes at least a first core portion, a first shell portion, and a second shell portion, wherein the first shell portion is adapted to interface with at least the second shell portion to form at least one first cavity between the core portion and the first and second shell portions. The core-shell mold may be inspected and assembled prior to connection of the wax gate component. At least a portion of the ceramic core-shell mold and the wax gate component is coated with a second ceramic material. The wax gate component is then removed to form a second cavity in fluid communication with the first cavity.

A method is for positioning a hollow workpiece obtained by casting and that enables the workpiece obtained in this way to be machined in accurate manner. The workpiece is obtained by a casting method involving a mold and a sacrificial core inserted inside the mold and serving to form at least one cavity in the workpiece. The workpiece includes surfaces of a first type defined during casting by the surfaces of the mold, and surfaces of a second type defined during casting by the surfaces of the core. A frame of reference for positioning the workpiece is constructed that includes at least three reference points (P1-P3) belonging to surfaces of the second type of the workpiece.

Radiation curable compositions for additive fabrication are described and claimed. Such compositions are particularly suited for investment casting applications, and include a cationically polymerizable component, a radically polymerizable component, a certain type of prescribed antimony-free, sulfonium salt-based cationic photoinitiator, and a free-radical photoinitiator. In other embodiments, the composition may also include a photosensitizer and/or a UV/absorber. Also described and claimed is a method for using a liquid radiation curable resin for additive fabrication with a certain type of prescribed antimony-free, sulfonium salt-based cationic photoinitiator and a certain type of prescribed photosensitizer in an investment casting process.

A method for making internal passages for use in investment casting processes, especially for gas turbine components such as blades or vanes. The apparatus includes a first mold cavity having grooves formed therein, a second mold cavity having a shape complementary to the final casting design and ceramic cores. Each groove of the first mold cavity has a depth equal to a radius of a certain number of ceramic cores which correspond to cooling channels. The ceramic cores are placed in the first mold cavity and fugitive wax is injected for temporary positioning of the cores. Two fugitive wax segments are formed about the cores. The fugitive segments locate the ceramic cores in the second mold cavity, and wax is injected about the cores and locating segments to form a pattern for investment casting process.

A method of fabricating an airfoil includes imaging a second end of the body portion to obtain image data, casting the tip portion utilizing the image data of the second end of the body portion and coupling a first end of the tip portion to the second end of the body portion. One or more features of the tip portion align with one or more features of the body portion. The method also includes additively manufacturing a core of the tip portion utilizing the image data and forming a casting mold about the core. The tip portion is cast in the casting mold. The coupling of the tip portion to the body portion including depositing a bonding material on a first end of the tip portion. An airfoil formed by the method is also disclosed.

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.

Radiation curable compositions for additive fabrication are described and claimed. Such compositions are particularly suited for investment casting applications, and include a cationically polymerizable component, a radically polymerizable component, a certain type of prescribed antimony-free, sulfonium salt-based cationic photoinitiator, and a free-radical photoinitiator. In other embodiments, the composition may also include a photosensitizer and/or a UV/absorber. Also described and claimed is a method for using a liquid radiation curable resin for additive fabrication with a certain type of prescribed antimony-free, sulfonium salt-based cationic photoinitiator and a certain type of prescribed photosensitizer in an investment casting process.

A method of investment casting includes casting a liquid nickel- or cobalt-based superalloy in an investment casting mold. The superalloy includes an yttrium alloying element that is subject to reactive loss during the casting. Loss of the yttrium is limited by using a zircon-containing facecoat on a refractory investment wall in the investment casting mold. The facecoat contacts the liquid nickel- or cobalt-based superalloy during the casting. Prior to the casting, a zircon-containing slurry is used to form the facecoat. After solidification of the nickel- or cobalt-based superalloy, the refractory investment wall is removed from the solidified superalloy.

An engine has a cylinder block formed by a block material and defining at least one cylinder. The block defines a lubrication circuit with fluid passages including an inlet passage, a main oil gallery, a crankshaft bearing lubrication passage, and a piston ring lubrication passage. The fluid passages are formed by continuous metal walls in contact with and surrounded by the block material. At least one of the fluid passages is curved. A method of forming a component with an internal pressurized lubrication circuit includes positioning a lost core insert in a tool, with the insert shaped to form a lubrication circuit. The lost core insert has a lost core material generally encapsulated in a continuous metal shell, and at least one curved section. Material is provided into the tool to form a body surrounding the lost core insert thereby forming a component preform.