Abstract: Environmental barrier coatings (EBCs) are disclosed having one or more sealing layers incorporated therein to inhibit ingress of corrosive materials into EBCs and their associated ceramic materials (CMCs). The sealing layers are yttrium oxide (Y2O3), lanthanum oxide (La2O3), ytterbium oxide (Yb2O3), hafnium oxide (HfO2), zirconium oxide (ZrO2), hafnium silicon oxide (HfSiO4), zirconium silicon oxide (ZrSiO4), ytterbium silicon oxide (Yb2Si2O7), and/or aluminum oxide (Al2O3) layers, and are applied by atomic layer deposition.

Abstract: To destructively remove a refractory metal casting core from a cast part the part is exposed to a combination of nitric acid and sulfuric acid.

Abstract: In accordance with the present invention, a casting system is provided which broadly comprises a core and a wax die spaced from said core, a refractory metal core having a first end seated within a slot in the core and a second end contacting the wax die for positioning the core relative to the wax die, and the refractory metal core having at least one of a mechanism for providing spring loading when closed in the wax die and a mechanism for mechanically locking the wax die to the core.

Abstract: An investment casting pattern is formed by forming a metallic first core element including at least one recess. The first core element is engaged to at least a mating one of an element of the die and a second core element. The recess serves to retain the first core element relative to the mating one. The die is assembled and a sacrificial material is introduced to the die to at least partially embed the first core element. The recess may be pre-formed prior to cutting the first core element from a larger sheet of material.

Abstract: To destructively remove a refractory metal casting core from a cast part the part is exposed to a combination of nitric acid and sulfuric acid.

Abstract: A sacrificial core is used for forming an interior space of a part and includes a ceramic core element and a first core element including a refractory metal element. The ceramic core element may be molded over the first core element or molded with assembly features permitting assembly with the first core element.

Abstract: A thermal-oxidative process is used to remove a casting core from a cast part.

Abstract: A method for forming or remanufacturing a component to have an internal space. A refractory metal blocking element is positioned with at least a portion to be within the internal space. A material is added by at least one of laser cladding and diffusion brazing, the blocking element at least partially blocking entry of the material to the internal space. The blocking element is removed.

Abstract: In accordance with the present invention, a casting system is provided which broadly comprises a core and a wax die spaced from said core, a refractory metal core having a first end seated within a slot in the core and a second end contacting the wax die for positioning the core relative to the wax die, and the refractory metal core having at least one of a mechanism for providing spring loading when closed in the wax die and a mechanism for mechanically locking the wax die to the core.

Abstract: An investment casting pattern is formed by forming a metallic first core element including at least one recess. The first core element is engaged to at least a mating one of an element of the die and a second core element. The recess serves to retain the first core element relative to the mating one. The die is assembled and a sacrificial material is introduced to the die to at least partially embed the first core element. The recess may be pre-formed prior to cutting the first core element from a larger sheet of material.

Abstract: Pre-molding of wax or similar sacrificial material over one or more cores facilitates a subsequent molding over a core assembly. Individual cores or groups thereof may be pre-molded in a wax body. One or more such wax bodies may be assembled with other bodies and/or other cores to facilitate a main wax molding of such assembly.

Abstract: An at least two step heating process is used to strengthen the shell of an investment casting mold including a refractory metal core. The first stage may occur under otherwise oxidizing conditions at a low enough temperature to avoid substantial core oxidation. The second stage may occur under essentially non-oxidizing conditions at a higher temperature.

Abstract: A sacrificial core for forming an interior space of a part includes a ceramic core element and a first core element including a refractory metal element. The ceramic core element may be molded over the first core element or molded with assembly features permitting assembly with the first core element.

Abstract: A casting system for forming a gas turbine engine component is provided. The casting system, in a first embodiment, comprises a shaped refractory metal sheet having a plurality of features for forming a plurality of film cooling passages, which features are formed from refractory metal material bent out of the sheet. The casting system for forming a gas turbine engine component in a second embodiment comprises a metal wall having an airfoil shape and a refractory metal core adjacent the metal wall and having a shape corresponding to the shape of the metal wall.

Abstract: In accordance with the present invention, a casting system is provided which broadly comprises a core and a wax die spaced from said core, a refractory metal core having a first end seated within a slot in the core and a second end contacting the wax die for positioning the core relative to the wax die, and the refractory metal core having at least one of a mechanism for providing spring loading when closed in the wax die and a mechanism for mechanically locking the wax die to the core.