Abstract: A method of forming a rotor for a turbine engine such that the rotor is formed of two materials including: an inner disk formed from a first material, such as steel, and an outer ring formed from a second material, such as a nickel alloy, having a larger thermal expansion coefficient than the first material forming the inner disk. The ring may include an inner aperture having a conical shape, and the disk may have an outer surface with a conical shape and a diameter with a portion that is larger than a portion of the ring. The ring may be heated such that the aperture expands to a size greater than the largest diameter of the inner disk. The ring may be positioned over the disk and allowed to cool to allow the ring to be attached to the disk. The ring and disk may then be co-forged.

Abstract: A nickel-based superalloy that forms a chromia scale in an oxidizing environment is disclosed. The alloy provides good oxidation resistance at temperatures below 900° C. in a dry or moist atmosphere. The superalloy is suited for components of gas or steam turbine engines including blades and vanes.

Abstract: A system for forming a surface coating on an outer surface of a foam for use with cooling system of turbine engines. The system may include removing filler from the outer surface of the foam to expose a porous structure of the foam, whereby portions of the porous structure extend outwardly from a newly formed outer surface of the filler. A surface layer may be applied to the outer surface of the filler and exposed portions of the porous structure, whereby the surface layer is attached to the porous structure at least in part due to mechanical interaction with the portions of the porous structure extending outwardly from the newly formed outer surface of the filler. The filler material may then be removed from the porous structure.