Abstract: Method making a multi-wall ceramic core for use in casting airfoils, such as turbine blades and vanes, wherein a fugitive pattern is formed having multiple thin wall pattern elements providing internal wall-forming spaces of a final core, the pattern is placed in a core molding die cavity having a desired core configuration, a fluid ceramic material is introduced into the die cavity about the pattern and between the pattern elements to form a ceramic core, and the core is removed from the die cavity. The fugitive pattern is selectively removed from the core to provide a multi-wall green core. The green core then is fired to develop core strength for casting and used to form an investment casting mold for casting an airfoil.

Abstract: A multi-wall ceramic core assembly and method of making same wherein a plurality of individual thin wall, arcuate (e.g. airfoil shaped) core elements are formed in respective master dies to have close tolerance mating locating features that substantially prevent penetration of molten metal between the interlocked features during casting, the individual core elements are fired on ceramic supports to have integral locating features, the prefired core elements are assembled together using the locator features of adjacent core elements, and the assembled core elements are held together using a fugitive material. The multi-wall ceramic core assembly so produced comprises the plurality of spaced apart thin wall, arcuate core elements and located by the mated close tolerance locating features.

Abstract: A plurality of individual thin wall, arcuate (e.g. airfoil shaped) core elements are formed in respective master dies to have integral interlocking locating features, the individual core elements are prefired in respective ceramic setter supports to have integral locating features, the prefired core elements are assembled together using the locator features of adjacent core elements, and the assembled core elements are adhered together using ceramic adhesive introduced at internal joints defined between mating interlocked locating features. The multi-wall ceramic core assembly so produced comprises the plurality of spaced apart thin wall, arcuate core elements and joined together by at the internal joints defined between the adhered interlocked locating features.

Abstract: A method of making a casting having an internal passage involves the steps of forming a core having an external surface configured to form the passage in the casting and having a plurality of integrally formed protrusions extending from the external surface at stressed regions thereof (e.g., thermally stressed regions) prone to be distorted from a master core configuration, and positioning the core in a pattern molding cavity by engagement of the protrusions with rigid walls defining the molding cavity such that the core is conformed substantially to a predetermined and/or empirically determined relationship between the master core configuration and the molding cavity as if the core corresponded to the master core configuration. A fugitive pattern corresponding to the casting to be formed is then molded about the external surface of the core while the core is supported in the aforementioned relationship relative to the molding cavity, whereby the wall thickness of the pattern is controlled about the core.